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|
/****************************************************************
* acm_core.c
*
* Copyright (C) 2005 IBM Corporation
*
* Author:
* Reiner Sailer <sailer@watson.ibm.com>
*
* Contributors:
* Stefan Berger <stefanb@watson.ibm.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, version 2 of the
* License.
*
* sHype access control module (ACM)
* This file handles initialization of the ACM
* as well as initializing/freeing security
* identifiers for domains (it calls on active
* policy hook functions).
*
*/
#include <xen/config.h>
#include <xen/errno.h>
#include <xen/types.h>
#include <xen/lib.h>
#include <xen/delay.h>
#include <xen/sched.h>
#include <xen/multiboot.h>
#include <acm/acm_hooks.h>
#include <acm/acm_endian.h>
/* debug:
* include/acm/acm_hooks.h defines a constant ACM_TRACE_MODE;
* define/undefine this constant to receive / suppress any
* security hook debug output of sHype
*
* include/public/acm.h defines a constant ACM_DEBUG
* define/undefine this constant to receive non-hook-related
* debug output.
*/
/* function prototypes */
void acm_init_chwall_policy(void);
void acm_init_ste_policy(void);
extern struct acm_operations acm_chinesewall_ops,
acm_simple_type_enforcement_ops, acm_null_ops;
/* global ACM policy (now dynamically determined at boot time) */
u16 acm_active_security_policy = ACM_POLICY_UNDEFINED;
/* global ops structs called by the hooks */
struct acm_operations *acm_primary_ops = NULL;
/* called in hook if-and-only-if primary succeeds */
struct acm_operations *acm_secondary_ops = NULL;
/* acm global binary policy (points to 'local' primary and secondary policies */
struct acm_binary_policy acm_bin_pol;
/* acm binary policy lock */
DEFINE_RWLOCK(acm_bin_pol_rwlock);
int
acm_set_policy_reference(u8 *buf, u32 buf_size)
{
struct acm_policy_reference_buffer *pr = (struct acm_policy_reference_buffer *)buf;
acm_bin_pol.policy_reference_name = (char *)xmalloc_array(u8, be32_to_cpu(pr->len));
if (!acm_bin_pol.policy_reference_name)
return -ENOMEM;
strlcpy(acm_bin_pol.policy_reference_name,
(char *)(buf + sizeof(struct acm_policy_reference_buffer)),
be32_to_cpu(pr->len));
printk("%s: Activating policy %s\n", __func__,
acm_bin_pol.policy_reference_name);
return 0;
}
int
acm_dump_policy_reference(u8 *buf, u32 buf_size)
{
struct acm_policy_reference_buffer *pr_buf = (struct acm_policy_reference_buffer *)buf;
int ret = sizeof(struct acm_policy_reference_buffer) + strlen(acm_bin_pol.policy_reference_name) + 1;
ret = (ret + 7) & ~7;
if (buf_size < ret)
return -EINVAL;
memset(buf, 0, ret);
pr_buf->len = cpu_to_be32(strlen(acm_bin_pol.policy_reference_name) + 1); /* including stringend '\0' */
strlcpy((char *)(buf + sizeof(struct acm_policy_reference_buffer)),
acm_bin_pol.policy_reference_name,
be32_to_cpu(pr_buf->len));
return ret;
}
int
acm_init_binary_policy(u32 policy_code)
{
int ret = ACM_OK;
acm_bin_pol.primary_policy_code = (policy_code & 0x0f);
acm_bin_pol.secondary_policy_code = (policy_code >> 4) & 0x0f;
write_lock(&acm_bin_pol_rwlock);
/* set primary policy component */
switch ((policy_code) & 0x0f)
{
case ACM_CHINESE_WALL_POLICY:
acm_init_chwall_policy();
acm_bin_pol.primary_policy_code = ACM_CHINESE_WALL_POLICY;
acm_primary_ops = &acm_chinesewall_ops;
break;
case ACM_SIMPLE_TYPE_ENFORCEMENT_POLICY:
acm_init_ste_policy();
acm_bin_pol.primary_policy_code = ACM_SIMPLE_TYPE_ENFORCEMENT_POLICY;
acm_primary_ops = &acm_simple_type_enforcement_ops;
break;
case ACM_NULL_POLICY:
acm_bin_pol.primary_policy_code = ACM_NULL_POLICY;
acm_primary_ops = &acm_null_ops;
break;
default:
/* Unknown policy not allowed primary */
ret = -EINVAL;
goto out;
}
/* secondary policy component part */
switch ((policy_code) >> 4)
{
case ACM_NULL_POLICY:
acm_bin_pol.secondary_policy_code = ACM_NULL_POLICY;
acm_secondary_ops = &acm_null_ops;
break;
case ACM_CHINESE_WALL_POLICY:
if (acm_bin_pol.primary_policy_code == ACM_CHINESE_WALL_POLICY)
{ /* not a valid combination */
ret = -EINVAL;
goto out;
}
acm_init_chwall_policy();
acm_bin_pol.secondary_policy_code = ACM_CHINESE_WALL_POLICY;
acm_secondary_ops = &acm_chinesewall_ops;
break;
case ACM_SIMPLE_TYPE_ENFORCEMENT_POLICY:
if (acm_bin_pol.primary_policy_code == ACM_SIMPLE_TYPE_ENFORCEMENT_POLICY)
{ /* not a valid combination */
ret = -EINVAL;
goto out;
}
acm_init_ste_policy();
acm_bin_pol.secondary_policy_code = ACM_SIMPLE_TYPE_ENFORCEMENT_POLICY;
acm_secondary_ops = &acm_simple_type_enforcement_ops;
break;
default:
ret = -EINVAL;
goto out;
}
out:
write_unlock(&acm_bin_pol_rwlock);
return ret;
}
int
acm_is_policy(char *buf, unsigned long len)
{
struct acm_policy_buffer *pol;
if (buf == NULL || len < sizeof(struct acm_policy_buffer))
return 0;
pol = (struct acm_policy_buffer *)buf;
return be32_to_cpu(pol->magic) == ACM_MAGIC;
}
static int
acm_setup(char *policy_start,
unsigned long policy_len)
{
int rc = ACM_OK;
struct acm_policy_buffer *pol;
if (policy_start == NULL || policy_len < sizeof(struct acm_policy_buffer))
return rc;
pol = (struct acm_policy_buffer *)policy_start;
if (be32_to_cpu(pol->magic) != ACM_MAGIC)
return rc;
rc = do_acm_set_policy((void *)policy_start, (u32)policy_len);
if (rc == ACM_OK)
{
printkd("Policy len 0x%lx, start at %p.\n",policy_len,policy_start);
}
else
{
printk("Invalid policy.\n");
/* load default policy later */
acm_active_security_policy = ACM_POLICY_UNDEFINED;
}
return rc;
}
int
acm_init(char *policy_start,
unsigned long policy_len)
{
int ret = ACM_OK;
/* first try to load the boot policy (uses its own locks) */
acm_setup(policy_start, policy_len);
if (acm_active_security_policy != ACM_POLICY_UNDEFINED)
{
printk("%s: Enforcing %s boot policy.\n", __func__,
ACM_POLICY_NAME(acm_active_security_policy));
goto out;
}
/* else continue with the minimal hardcoded default startup policy */
printk("%s: Loading default policy (%s).\n",
__func__, ACM_POLICY_NAME(ACM_DEFAULT_SECURITY_POLICY));
if (acm_init_binary_policy(ACM_DEFAULT_SECURITY_POLICY)) {
ret = -EINVAL;
goto out;
}
acm_active_security_policy = ACM_DEFAULT_SECURITY_POLICY;
if (acm_active_security_policy != ACM_NULL_POLICY)
acm_bin_pol.policy_reference_name = "DEFAULT";
else
acm_bin_pol.policy_reference_name = "NULL";
out:
if (ret != ACM_OK)
{
printk("%s: Error initializing policies.\n", __func__);
/* here one could imagine a clean panic */
return -EINVAL;
}
return ret;
}
int
acm_init_domain_ssid(domid_t id, ssidref_t ssidref)
{
struct acm_ssid_domain *ssid;
struct domain *subj = get_domain_by_id(id);
int ret1, ret2;
if (subj == NULL)
|
