blob: 33cea5ae75b9a11a44c7d32dfd24ec8a4f2079eb [file] [log] [blame]
/*
* Class and permission mappings.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdbool.h>
#include <selinux/selinux.h>
#include <selinux/avc.h>
#include "callbacks.h"
#include "mapping.h"
#include "selinux_internal.h"
/*
* Class and permission mappings
*/
struct selinux_mapping {
security_class_t value; /* real, kernel value */
unsigned num_perms;
access_vector_t perms[sizeof(access_vector_t) * 8];
};
static struct selinux_mapping *current_mapping = NULL;
static security_class_t current_mapping_size = 0;
/*
* Mapping setting function
*/
int
selinux_set_mapping(struct security_class_mapping *map)
{
size_t size = sizeof(struct selinux_mapping);
security_class_t i, j;
unsigned k;
bool print_unknown_handle = false;
bool reject = (security_reject_unknown() == 1);
bool deny = (security_deny_unknown() == 1);
free(current_mapping);
current_mapping = NULL;
current_mapping_size = 0;
if (avc_reset() < 0)
goto err;
/* Find number of classes in the input mapping */
if (!map) {
errno = EINVAL;
goto err;
}
i = 0;
while (map[i].name)
i++;
/* Allocate space for the class records, plus one for class zero */
current_mapping = (struct selinux_mapping *)calloc(++i, size);
if (!current_mapping)
goto err;
/* Store the raw class and permission values */
j = 0;
while (map[j].name) {
struct security_class_mapping *p_in = map + (j++);
struct selinux_mapping *p_out = current_mapping + j;
p_out->value = string_to_security_class(p_in->name);
if (!p_out->value) {
selinux_log(SELINUX_INFO,
"SELinux: Class %s not defined in policy.\n",
p_in->name);
if (reject)
goto err2;
p_out->num_perms = 0;
print_unknown_handle = true;
continue;
}
k = 0;
while (p_in->perms[k]) {
/* An empty permission string skips ahead */
if (!*p_in->perms[k]) {
k++;
continue;
}
p_out->perms[k] = string_to_av_perm(p_out->value,
p_in->perms[k]);
if (!p_out->perms[k]) {
selinux_log(SELINUX_INFO,
"SELinux: Permission %s in class %s not defined in policy.\n",
p_in->perms[k], p_in->name);
if (reject)
goto err2;
print_unknown_handle = true;
}
k++;
}
p_out->num_perms = k;
}
if (print_unknown_handle)
selinux_log(SELINUX_INFO,
"SELinux: the above unknown classes and permissions will be %s\n",
deny ? "denied" : "allowed");
/* Set the mapping size here so the above lookups are "raw" */
current_mapping_size = i;
return 0;
err2:
free(current_mapping);
current_mapping = NULL;
current_mapping_size = 0;
err:
return -1;
}
/*
* Get real, kernel values from mapped values
*/
security_class_t
unmap_class(security_class_t tclass)
{
if (tclass < current_mapping_size)
return current_mapping[tclass].value;
/* If here no mapping set or the class requested is not valid. */
if (current_mapping_size != 0) {
errno = EINVAL;
return 0;
}
else
return tclass;
}
access_vector_t
unmap_perm(security_class_t tclass, access_vector_t tperm)
{
if (tclass < current_mapping_size) {
unsigned i;
access_vector_t kperm = 0;
for (i=0; i<current_mapping[tclass].num_perms; i++)
if (tperm & (1<<i)) {
kperm |= current_mapping[tclass].perms[i];
tperm &= ~(1<<i);
}
return kperm;
}
/* If here no mapping set or the perm requested is not valid. */
if (current_mapping_size != 0) {
errno = EINVAL;
return 0;
}
else
return tperm;
}
/*
* Get mapped values from real, kernel values
*/
security_class_t
map_class(security_class_t kclass)
{
security_class_t i;
for (i=0; i<current_mapping_size; i++)
if (current_mapping[i].value == kclass)
return i;
/* If here no mapping set or the class requested is not valid. */
if (current_mapping_size != 0) {
errno = EINVAL;
return 0;
}
else
return kclass;
}
access_vector_t
map_perm(security_class_t tclass, access_vector_t kperm)
{
if (tclass < current_mapping_size) {
unsigned i;
access_vector_t tperm = 0;
for (i=0; i<current_mapping[tclass].num_perms; i++)
if (kperm & current_mapping[tclass].perms[i]) {
tperm |= 1<<i;
kperm &= ~current_mapping[tclass].perms[i];
}
if (tperm == 0) {
errno = EINVAL;
return 0;
}
else
return tperm;
}
return kperm;
}
void
map_decision(security_class_t tclass, struct av_decision *avd)
{
if (tclass < current_mapping_size) {
bool allow_unknown = (security_deny_unknown() == 0);
struct selinux_mapping *mapping = &current_mapping[tclass];
unsigned int i, n = mapping->num_perms;
access_vector_t result;
for (i = 0, result = 0; i < n; i++) {
if (avd->allowed & mapping->perms[i])
result |= 1<<i;
else if (allow_unknown && !mapping->perms[i])
result |= 1<<i;
}
avd->allowed = result;
for (i = 0, result = 0; i < n; i++) {
if (avd->decided & mapping->perms[i])
result |= 1<<i;
else if (allow_unknown && !mapping->perms[i])
result |= 1<<i;
}
avd->decided = result;
for (i = 0, result = 0; i < n; i++)
if (avd->auditallow & mapping->perms[i])
result |= 1<<i;
avd->auditallow = result;
for (i = 0, result = 0; i < n; i++) {
if (avd->auditdeny & mapping->perms[i])
result |= 1<<i;
else if (!allow_unknown && !mapping->perms[i])
result |= 1<<i;
}
/*
* Make sure we audit denials for any permission check
* beyond the mapping->num_perms since this indicates
* a bug in the object manager.
*/
for (; i < (sizeof(result)*8); i++)
result |= 1<<i;
avd->auditdeny = result;
}
}