1 files changed, 203 insertions, 0 deletions

diff --git a/security/security.c b/security/security.c
new file mode 100644
index 000000000000..ed5fb80769c3
--- /dev/null
+++ b/security/security.c
@@ -0,0 +1,203 @@
+/*
+ * Security plug functions
+ *
+ * Copyright (C) 2001 WireX Communications, Inc <chris@wirex.com>
+ * Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com>
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/security.h>
+
+#define SECURITY_FRAMEWORK_VERSION      "1.0.0"
+
+/* things that live in dummy.c */
+extern struct security_operations dummy_security_ops;
+extern void security_fixup_ops(struct security_operations *ops);
+
+struct security_operations *security_ops;       /* Initialized to NULL */
+
+static inline int verify(struct security_operations *ops)
+{
+        /* verify the security_operations structure exists */
+        if (!ops)
+                return -EINVAL;
+        security_fixup_ops(ops);
+        return 0;
+}
+
+static void __init do_security_initcalls(void)
+{
+        initcall_t *call;
+        call = __security_initcall_start;
+        while (call < __security_initcall_end) {
+                (*call) ();
+                call++;
+        }
+}
+
+/**
+ * security_init - initializes the security framework
+ *
+ * This should be called early in the kernel initialization sequence.
+ */
+int __init security_init(void)
+{
+        printk(KERN_INFO "Security Framework v" SECURITY_FRAMEWORK_VERSION
+               " initialized\n");
+
+        if (verify(&dummy_security_ops)) {
+                printk(KERN_ERR "%s could not verify "
+                       "dummy_security_ops structure.\n", __FUNCTION__);
+                return -EIO;
+        }
+
+        security_ops = &dummy_security_ops;
+        do_security_initcalls();
+
+        return 0;
+}
+
+/**
+ * register_security - registers a security framework with the kernel
+ * @ops: a pointer to the struct security_options that is to be registered
+ *
+ * This function is to allow a security module to register itself with the
+ * kernel security subsystem.  Some rudimentary checking is done on the @ops
+ * value passed to this function.  A call to unregister_security() should be
+ * done to remove this security_options structure from the kernel.
+ *
+ * If there is already a security module registered with the kernel,
+ * an error will be returned.  Otherwise 0 is returned on success.
+ */
+int register_security(struct security_operations *ops)
+{
+        if (verify(ops)) {
+                printk(KERN_DEBUG "%s could not verify "
+                       "security_operations structure.\n", __FUNCTION__);
+                return -EINVAL;
+        }
+
+        if (security_ops != &dummy_security_ops)
+                return -EAGAIN;
+
+        security_ops = ops;
+
+        return 0;
+}
+
+/**
+ * unregister_security - unregisters a security framework with the kernel
+ * @ops: a pointer to the struct security_options that is to be registered
+ *
+ * This function removes a struct security_operations variable that had
+ * previously been registered with a successful call to register_security().
+ *
+ * If @ops does not match the valued previously passed to register_security()
+ * an error is returned.  Otherwise the default security options is set to the
+ * the dummy_security_ops structure, and 0 is returned.
+ */
+int unregister_security(struct security_operations *ops)
+{
+        if (ops != security_ops) {
+                printk(KERN_INFO "%s: trying to unregister "
+                       "a security_opts structure that is not "
+                       "registered, failing.\n", __FUNCTION__);
+                return -EINVAL;
+        }
+
+        security_ops = &dummy_security_ops;
+
+        return 0;
+}
+
+/**
+ * mod_reg_security - allows security modules to be "stacked"
+ * @name: a pointer to a string with the name of the security_options to be registered
+ * @ops: a pointer to the struct security_options that is to be registered
+ *
+ * This function allows security modules to be stacked if the currently loaded
+ * security module allows this to happen.  It passes the @name and @ops to the
+ * register_security function of the currently loaded security module.
+ *
+ * The return value depends on the currently loaded security module, with 0 as
+ * success.
+ */
+int mod_reg_security(const char *name, struct security_operations *ops)
+{
+        if (verify(ops)) {
+                printk(KERN_INFO "%s could not verify "
+                       "security operations.\n", __FUNCTION__);
+                return -EINVAL;
+        }
+
+        if (ops == security_ops) {
+                printk(KERN_INFO "%s security operations "
+                       "already registered.\n", __FUNCTION__);
+                return -EINVAL;
+        }
+
+        return security_ops->register_security(name, ops);
+}
+
+/**
+ * mod_unreg_security - allows a security module registered with mod_reg_security() to be unloaded
+ * @name: a pointer to a string with the name of the security_options to be removed
+ * @ops: a pointer to the struct security_options that is to be removed
+ *
+ * This function allows security modules that have been successfully registered
+ * with a call to mod_reg_security() to be unloaded from the system.
+ * This calls the currently loaded security module's unregister_security() call
+ * with the @name and @ops variables.
+ *
+ * The return value depends on the currently loaded security module, with 0 as
+ * success.
+ */
+int mod_unreg_security(const char *name, struct security_operations *ops)
+{
+        if (ops == security_ops) {
+                printk(KERN_INFO "%s invalid attempt to unregister "
+                       " primary security ops.\n", __FUNCTION__);
+                return -EINVAL;
+        }
+
+        return security_ops->unregister_security(name, ops);
+}
+
+/**
+ * capable - calls the currently loaded security module's capable() function with the specified capability
+ * @cap: the requested capability level.
+ *
+ * This function calls the currently loaded security module's capable()
+ * function with a pointer to the current task and the specified @cap value.
+ *
+ * This allows the security module to implement the capable function call
+ * however it chooses to.
+ */
+int capable(int cap)
+{
+        if (security_ops->capable(current, cap)) {
+                /* capability denied */
+                return 0;
+        }
+
+        /* capability granted */
+        current->flags |= PF_SUPERPRIV;
+        return 1;
+}
+
+EXPORT_SYMBOL_GPL(register_security);
+EXPORT_SYMBOL_GPL(unregister_security);
+EXPORT_SYMBOL_GPL(mod_reg_security);
+EXPORT_SYMBOL_GPL(mod_unreg_security);
+EXPORT_SYMBOL(capable);
+EXPORT_SYMBOL(security_ops);