linux-sg2042/security/tomoyo/load_policy.c

82 lines
2.2 KiB
C

/*
* security/tomoyo/load_policy.c
*
* Policy loader launcher for TOMOYO.
*
* Copyright (C) 2005-2010 NTT DATA CORPORATION
*/
#include "common.h"
/* path to policy loader */
static const char *tomoyo_loader = "/sbin/tomoyo-init";
/**
* tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
*
* Returns true if /sbin/tomoyo-init exists, false otherwise.
*/
static bool tomoyo_policy_loader_exists(void)
{
/*
* Don't activate MAC if the policy loader doesn't exist.
* If the initrd includes /sbin/init but real-root-dev has not
* mounted on / yet, activating MAC will block the system since
* policies are not loaded yet.
* Thus, let do_execve() call this function everytime.
*/
struct path path;
if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
printk(KERN_INFO "Not activating Mandatory Access Control now "
"since %s doesn't exist.\n", tomoyo_loader);
return false;
}
path_put(&path);
return true;
}
/**
* tomoyo_load_policy - Run external policy loader to load policy.
*
* @filename: The program about to start.
*
* This function checks whether @filename is /sbin/init , and if so
* invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
* and then continues invocation of /sbin/init.
* /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
* writes to /sys/kernel/security/tomoyo/ interfaces.
*
* Returns nothing.
*/
void tomoyo_load_policy(const char *filename)
{
char *argv[2];
char *envp[3];
if (tomoyo_policy_loaded)
return;
/*
* Check filename is /sbin/init or /sbin/tomoyo-start.
* /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
* be passed.
* You can create /sbin/tomoyo-start by
* "ln -s /bin/true /sbin/tomoyo-start".
*/
if (strcmp(filename, "/sbin/init") &&
strcmp(filename, "/sbin/tomoyo-start"))
return;
if (!tomoyo_policy_loader_exists())
return;
printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
tomoyo_loader);
argv[0] = (char *) tomoyo_loader;
argv[1] = NULL;
envp[0] = "HOME=/";
envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
envp[2] = NULL;
call_usermodehelper(argv[0], argv, envp, 1);
tomoyo_check_profile();
}