/* * 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/capability.h> #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); } EXPORT_SYMBOL_GPL(register_security); EXPORT_SYMBOL_GPL(unregister_security); EXPORT_SYMBOL_GPL(mod_reg_security); EXPORT_SYMBOL_GPL(mod_unreg_security); EXPORT_SYMBOL(security_ops);