/*
* 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/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/security.h>
/* Boot-time LSM user choice */
static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1];
/* 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 */
/* amount of vm to protect from userspace access */
unsigned long mmap_min_addr = CONFIG_SECURITY_DEFAULT_MMAP_MIN_ADDR;
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 initialized\n");
if (verify(&dummy_security_ops)) {
printk(KERN_ERR "%s could not verify "
"dummy_security_ops structure.\n", __func__);
return -EIO;
}
security_ops = &dummy_security_ops;
do_security_initcalls();
return 0;
}
/* Save user chosen LSM */
static int __init choose_lsm(char *str)
{
strncpy(chosen_lsm, str, SECURITY_NAME_MAX);
return 1;
}
__setup("security=", choose_lsm);
/**
* security_module_enable - Load given security module on boot ?
* @ops: a pointer to the struct security_operations that is to be checked.
*
* Each LSM must pass this method before registering its own operations
* to avoid security registration races. This method may also be used
* to check if your LSM is currently loaded during kernel initialization.
*
* Return true if:
* -The passed LSM is the one chosen by user at boot time,
* -or user didsn't specify a specific LSM and we're the first to ask
* for registeration permissoin,
* -or the passed LSM is currently loaded.
* Otherwise, return false.
*/
int __init security_module_enable(struct security_operations *ops)
{
if (!*chosen_lsm)
strncpy(chosen_lsm, ops->name, SECURITY_NAME_MAX);
else if (strncmp(ops->name, chosen_lsm, SECURITY_NAME_MAX))
return 0;
return 1;
}
/**
* 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. You'll need to check first if your LSM
* is allowed to register its @ops by calling security_module_enable(@ops).
*
* 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", __func__);
return -EINVAL;
}
if (security_ops != &dummy_security_ops)
return -EAGAIN;
security_ops = 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 (