|
/* Author : Stephen Smalley, <sds@tycho.nsa.gov> */
|
|
/*
|
* Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
|
* Tuned number of hash slots for avtab to reduce memory usage
|
*/
|
|
/* Updated: Frank Mayer <mayerf@tresys.com>
|
* and Karl MacMillan <kmacmillan@mentalrootkit.com>
|
*
|
* Added conditional policy language extensions
|
*
|
* Updated: Red Hat, Inc. James Morris <jmorris@redhat.com>
|
*
|
* Code cleanup
|
*
|
* Updated: Karl MacMillan <kmacmillan@mentalrootkit.com>
|
*
|
* Copyright (C) 2003 Tresys Technology, LLC
|
* Copyright (C) 2003,2007 Red Hat, Inc.
|
*
|
* This library is free software; you can redistribute it and/or
|
* modify it under the terms of the GNU Lesser General Public
|
* License as published by the Free Software Foundation; either
|
* version 2.1 of the License, or (at your option) any later version.
|
*
|
* This library is distributed in the hope that it will be useful,
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
* Lesser General Public License for more details.
|
*
|
* You should have received a copy of the GNU Lesser General Public
|
* License along with this library; if not, write to the Free Software
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
*/
|
|
/* FLASK */
|
|
/*
|
* Implementation of the access vector table type.
|
*/
|
|
#include <stdlib.h>
|
#include <sepol/policydb/avtab.h>
|
#include <sepol/policydb/policydb.h>
|
#include <sepol/errcodes.h>
|
|
#include "debug.h"
|
#include "private.h"
|
|
/* Based on MurmurHash3, written by Austin Appleby and placed in the
|
* public domain.
|
*/
|
static inline int avtab_hash(struct avtab_key *keyp, uint32_t mask)
|
{
|
static const uint32_t c1 = 0xcc9e2d51;
|
static const uint32_t c2 = 0x1b873593;
|
static const uint32_t r1 = 15;
|
static const uint32_t r2 = 13;
|
static const uint32_t m = 5;
|
static const uint32_t n = 0xe6546b64;
|
|
uint32_t hash = 0;
|
|
#define mix(input) { \
|
uint32_t v = input; \
|
v *= c1; \
|
v = (v << r1) | (v >> (32 - r1)); \
|
v *= c2; \
|
hash ^= v; \
|
hash = (hash << r2) | (hash >> (32 - r2)); \
|
hash = hash * m + n; \
|
}
|
|
mix(keyp->target_class);
|
mix(keyp->target_type);
|
mix(keyp->source_type);
|
|
#undef mix
|
|
hash ^= hash >> 16;
|
hash *= 0x85ebca6b;
|
hash ^= hash >> 13;
|
hash *= 0xc2b2ae35;
|
hash ^= hash >> 16;
|
|
return hash & mask;
|
}
|
|
static avtab_ptr_t
|
avtab_insert_node(avtab_t * h, int hvalue, avtab_ptr_t prev, avtab_key_t * key,
|
avtab_datum_t * datum)
|
{
|
avtab_ptr_t newnode;
|
avtab_extended_perms_t *xperms;
|
|
newnode = (avtab_ptr_t) malloc(sizeof(struct avtab_node));
|
if (newnode == NULL)
|
return NULL;
|
memset(newnode, 0, sizeof(struct avtab_node));
|
newnode->key = *key;
|
|
if (key->specified & AVTAB_XPERMS) {
|
xperms = calloc(1, sizeof(avtab_extended_perms_t));
|
if (xperms == NULL) {
|
free(newnode);
|
return NULL;
|
}
|
if (datum->xperms) /* else caller populates xperms */
|
*xperms = *(datum->xperms);
|
|
newnode->datum.xperms = xperms;
|
/* data is usually ignored with xperms, except in the case of
|
* neverallow checking, which requires permission bits to be set.
|
* So copy data so it is set in the avtab
|
*/
|
newnode->datum.data = datum->data;
|
} else {
|
newnode->datum = *datum;
|
}
|
|
if (prev) {
|
newnode->next = prev->next;
|
prev->next = newnode;
|
} else {
|
newnode->next = h->htable[hvalue];
|
h->htable[hvalue] = newnode;
|
}
|
|
h->nel++;
|
return newnode;
|
}
|
|
int avtab_insert(avtab_t * h, avtab_key_t * key, avtab_datum_t * datum)
|
{
|
int hvalue;
|
avtab_ptr_t prev, cur, newnode;
|
uint16_t specified =
|
key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD);
|
|
if (!h || !h->htable)
|
return SEPOL_ENOMEM;
|
|
hvalue = avtab_hash(key, h->mask);
|
for (prev = NULL, cur = h->htable[hvalue];
|
cur; prev = cur, cur = cur->next) {
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class == cur->key.target_class &&
|
(specified & cur->key.specified)) {
|
/* Extended permissions are not necessarily unique */
|
if (specified & AVTAB_XPERMS)
|
break;
|
return SEPOL_EEXIST;
|
}
|
if (key->source_type < cur->key.source_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type < cur->key.target_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class < cur->key.target_class)
|
break;
|
}
|
|
newnode = avtab_insert_node(h, hvalue, prev, key, datum);
|
if (!newnode)
|
return SEPOL_ENOMEM;
|
|
return 0;
|
}
|
|
/* Unlike avtab_insert(), this function allow multiple insertions of the same
|
* key/specified mask into the table, as needed by the conditional avtab.
|
* It also returns a pointer to the node inserted.
|
*/
|
avtab_ptr_t
|
avtab_insert_nonunique(avtab_t * h, avtab_key_t * key, avtab_datum_t * datum)
|
{
|
int hvalue;
|
avtab_ptr_t prev, cur, newnode;
|
uint16_t specified =
|
key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD);
|
|
if (!h || !h->htable)
|
return NULL;
|
hvalue = avtab_hash(key, h->mask);
|
for (prev = NULL, cur = h->htable[hvalue];
|
cur; prev = cur, cur = cur->next) {
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class == cur->key.target_class &&
|
(specified & cur->key.specified))
|
break;
|
if (key->source_type < cur->key.source_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type < cur->key.target_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class < cur->key.target_class)
|
break;
|
}
|
newnode = avtab_insert_node(h, hvalue, prev, key, datum);
|
|
return newnode;
|
}
|
|
avtab_datum_t *avtab_search(avtab_t * h, avtab_key_t * key)
|
{
|
int hvalue;
|
avtab_ptr_t cur;
|
uint16_t specified =
|
key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD);
|
|
if (!h || !h->htable)
|
return NULL;
|
|
hvalue = avtab_hash(key, h->mask);
|
for (cur = h->htable[hvalue]; cur; cur = cur->next) {
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class == cur->key.target_class &&
|
(specified & cur->key.specified))
|
return &cur->datum;
|
|
if (key->source_type < cur->key.source_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type < cur->key.target_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class < cur->key.target_class)
|
break;
|
}
|
|
return NULL;
|
}
|
|
/* This search function returns a node pointer, and can be used in
|
* conjunction with avtab_search_next_node()
|
*/
|
avtab_ptr_t avtab_search_node(avtab_t * h, avtab_key_t * key)
|
{
|
int hvalue;
|
avtab_ptr_t cur;
|
uint16_t specified =
|
key->specified & ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD);
|
|
if (!h || !h->htable)
|
return NULL;
|
|
hvalue = avtab_hash(key, h->mask);
|
for (cur = h->htable[hvalue]; cur; cur = cur->next) {
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class == cur->key.target_class &&
|
(specified & cur->key.specified))
|
return cur;
|
|
if (key->source_type < cur->key.source_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type < cur->key.target_type)
|
break;
|
if (key->source_type == cur->key.source_type &&
|
key->target_type == cur->key.target_type &&
|
key->target_class < cur->key.target_class)
|
break;
|
}
|
return NULL;
|
}
|
|
avtab_ptr_t avtab_search_node_next(avtab_ptr_t node, int specified)
|
{
|
avtab_ptr_t cur;
|
|
if (!node)
|
return NULL;
|
|
specified &= ~(AVTAB_ENABLED | AVTAB_ENABLED_OLD);
|
for (cur = node->next; cur; cur = cur->next) {
|
if (node->key.source_type == cur->key.source_type &&
|
node->key.target_type == cur->key.target_type &&
|
node->key.target_class == cur->key.target_class &&
|
(specified & cur->key.specified))
|
return cur;
|
|
if (node->key.source_type < cur->key.source_type)
|
break;
|
if (node->key.source_type == cur->key.source_type &&
|
node->key.target_type < cur->key.target_type)
|
break;
|
if (node->key.source_type == cur->key.source_type &&
|
node->key.target_type == cur->key.target_type &&
|
node->key.target_class < cur->key.target_class)
|
break;
|
}
|
return NULL;
|
}
|
|
void avtab_destroy(avtab_t * h)
|
{
|
unsigned int i;
|
avtab_ptr_t cur, temp;
|
|
if (!h || !h->htable)
|
return;
|
|
for (i = 0; i < h->nslot; i++) {
|
cur = h->htable[i];
|
while (cur != NULL) {
|
if (cur->key.specified & AVTAB_XPERMS) {
|
free(cur->datum.xperms);
|
}
|
temp = cur;
|
cur = cur->next;
|
free(temp);
|
}
|
h->htable[i] = NULL;
|
}
|
free(h->htable);
|
h->htable = NULL;
|
h->nslot = 0;
|
h->mask = 0;
|
}
|
|
int avtab_map(avtab_t * h,
|
int (*apply) (avtab_key_t * k,
|
avtab_datum_t * d, void *args), void *args)
|
{
|
unsigned int i;
|
int ret;
|
avtab_ptr_t cur;
|
|
if (!h)
|
return 0;
|
|
for (i = 0; i < h->nslot; i++) {
|
cur = h->htable[i];
|
while (cur != NULL) {
|
ret = apply(&cur->key, &cur->datum, args);
|
if (ret)
|
return ret;
|
cur = cur->next;
|
}
|
}
|
return 0;
|
}
|
|
int avtab_init(avtab_t * h)
|
{
|
h->htable = NULL;
|
h->nel = 0;
|
return 0;
|
}
|
|
int avtab_alloc(avtab_t *h, uint32_t nrules)
|
{
|
uint32_t mask = 0;
|
uint32_t shift = 0;
|
uint32_t work = nrules;
|
uint32_t nslot = 0;
|
|
if (nrules == 0)
|
goto out;
|
|
while (work) {
|
work = work >> 1;
|
shift++;
|
}
|
if (shift > 2)
|
shift = shift - 2;
|
nslot = 1 << shift;
|
if (nslot > MAX_AVTAB_HASH_BUCKETS)
|
nslot = MAX_AVTAB_HASH_BUCKETS;
|
mask = nslot - 1;
|
|
h->htable = calloc(nslot, sizeof(avtab_ptr_t));
|
if (!h->htable)
|
return -1;
|
out:
|
h->nel = 0;
|
h->nslot = nslot;
|
h->mask = mask;
|
return 0;
|
}
|
|
void avtab_hash_eval(avtab_t * h, char *tag)
|
{
|
unsigned int i, chain_len, slots_used, max_chain_len;
|
avtab_ptr_t cur;
|
|
slots_used = 0;
|
max_chain_len = 0;
|
for (i = 0; i < h->nslot; i++) {
|
cur = h->htable[i];
|
if (cur) {
|
slots_used++;
|
chain_len = 0;
|
while (cur) {
|
chain_len++;
|
cur = cur->next;
|
}
|
|
if (chain_len > max_chain_len)
|
max_chain_len = chain_len;
|
}
|
}
|
|
printf
|
("%s: %d entries and %d/%d buckets used, longest chain length %d\n",
|
tag, h->nel, slots_used, h->nslot, max_chain_len);
|
}
|
|
/* Ordering of datums in the original avtab format in the policy file. */
|
static uint16_t spec_order[] = {
|
AVTAB_ALLOWED,
|
AVTAB_AUDITDENY,
|
AVTAB_AUDITALLOW,
|
AVTAB_TRANSITION,
|
AVTAB_CHANGE,
|
AVTAB_MEMBER,
|
AVTAB_XPERMS_ALLOWED,
|
AVTAB_XPERMS_AUDITALLOW,
|
AVTAB_XPERMS_DONTAUDIT
|
};
|
|
int avtab_read_item(struct policy_file *fp, uint32_t vers, avtab_t * a,
|
int (*insertf) (avtab_t * a, avtab_key_t * k,
|
avtab_datum_t * d, void *p), void *p)
|
{
|
uint8_t buf8;
|
uint16_t buf16[4], enabled;
|
uint32_t buf32[8], items, items2, val;
|
avtab_key_t key;
|
avtab_datum_t datum;
|
avtab_extended_perms_t xperms;
|
unsigned set;
|
unsigned int i;
|
int rc;
|
|
memset(&key, 0, sizeof(avtab_key_t));
|
memset(&datum, 0, sizeof(avtab_datum_t));
|
memset(&xperms, 0, sizeof(avtab_extended_perms_t));
|
|
if (vers < POLICYDB_VERSION_AVTAB) {
|
rc = next_entry(buf32, fp, sizeof(uint32_t));
|
if (rc < 0) {
|
ERR(fp->handle, "truncated entry");
|
return -1;
|
}
|
items2 = le32_to_cpu(buf32[0]);
|
|
if (items2 < 5 || items2 > ARRAY_SIZE(buf32)) {
|
ERR(fp->handle, "invalid item count");
|
return -1;
|
}
|
|
rc = next_entry(buf32, fp, sizeof(uint32_t) * items2);
|
if (rc < 0) {
|
ERR(fp->handle, "truncated entry");
|
return -1;
|
}
|
|
items = 0;
|
val = le32_to_cpu(buf32[items++]);
|
key.source_type = (uint16_t) val;
|
if (key.source_type != val) {
|
ERR(fp->handle, "truncated source type");
|
return -1;
|
}
|
val = le32_to_cpu(buf32[items++]);
|
key.target_type = (uint16_t) val;
|
if (key.target_type != val) {
|
ERR(fp->handle, "truncated target type");
|
return -1;
|
}
|
val = le32_to_cpu(buf32[items++]);
|
key.target_class = (uint16_t) val;
|
if (key.target_class != val) {
|
ERR(fp->handle, "truncated target class");
|
return -1;
|
}
|
|
val = le32_to_cpu(buf32[items++]);
|
enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
|
|
if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
|
ERR(fp->handle, "null entry");
|
return -1;
|
}
|
if ((val & AVTAB_AV) && (val & AVTAB_TYPE)) {
|
ERR(fp->handle, "entry has both access "
|
"vectors and types");
|
return -1;
|
}
|
|
for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
|
if (val & spec_order[i]) {
|
key.specified = spec_order[i] | enabled;
|
datum.data = le32_to_cpu(buf32[items++]);
|
rc = insertf(a, &key, &datum, p);
|
if (rc)
|
return rc;
|
}
|
}
|
|
if (items != items2) {
|
ERR(fp->handle, "entry only had %d items, "
|
"expected %d", items2, items);
|
return -1;
|
}
|
return 0;
|
}
|
|
rc = next_entry(buf16, fp, sizeof(uint16_t) * 4);
|
if (rc < 0) {
|
ERR(fp->handle, "truncated entry");
|
return -1;
|
}
|
items = 0;
|
key.source_type = le16_to_cpu(buf16[items++]);
|
key.target_type = le16_to_cpu(buf16[items++]);
|
key.target_class = le16_to_cpu(buf16[items++]);
|
key.specified = le16_to_cpu(buf16[items++]);
|
|
set = 0;
|
for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
|
if (key.specified & spec_order[i])
|
set++;
|
}
|
if (!set || set > 1) {
|
ERR(fp->handle, "more than one specifier");
|
return -1;
|
}
|
|
if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) &&
|
(key.specified & AVTAB_XPERMS)) {
|
ERR(fp->handle, "policy version %u does not support extended "
|
"permissions rules and one was specified\n", vers);
|
return -1;
|
} else if (key.specified & AVTAB_XPERMS) {
|
rc = next_entry(&buf8, fp, sizeof(uint8_t));
|
if (rc < 0) {
|
ERR(fp->handle, "truncated entry");
|
return -1;
|
}
|
xperms.specified = buf8;
|
rc = next_entry(&buf8, fp, sizeof(uint8_t));
|
if (rc < 0) {
|
ERR(fp->handle, "truncated entry");
|
return -1;
|
}
|
xperms.driver = buf8;
|
rc = next_entry(buf32, fp, sizeof(uint32_t)*8);
|
if (rc < 0) {
|
ERR(fp->handle, "truncated entry");
|
return -1;
|
}
|
for (i = 0; i < ARRAY_SIZE(xperms.perms); i++)
|
xperms.perms[i] = le32_to_cpu(buf32[i]);
|
datum.xperms = &xperms;
|
} else {
|
rc = next_entry(buf32, fp, sizeof(uint32_t));
|
if (rc < 0) {
|
ERR(fp->handle, "truncated entry");
|
return -1;
|
}
|
datum.data = le32_to_cpu(*buf32);
|
}
|
return insertf(a, &key, &datum, p);
|
}
|
|
static int avtab_insertf(avtab_t * a, avtab_key_t * k, avtab_datum_t * d,
|
void *p __attribute__ ((unused)))
|
{
|
return avtab_insert(a, k, d);
|
}
|
|
int avtab_read(avtab_t * a, struct policy_file *fp, uint32_t vers)
|
{
|
unsigned int i;
|
int rc;
|
uint32_t buf[1];
|
uint32_t nel;
|
|
rc = next_entry(buf, fp, sizeof(uint32_t));
|
if (rc < 0) {
|
ERR(fp->handle, "truncated table");
|
goto bad;
|
}
|
nel = le32_to_cpu(buf[0]);
|
if (!nel) {
|
ERR(fp->handle, "table is empty");
|
goto bad;
|
}
|
|
rc = avtab_alloc(a, nel);
|
if (rc) {
|
ERR(fp->handle, "out of memory");
|
goto bad;
|
}
|
|
for (i = 0; i < nel; i++) {
|
rc = avtab_read_item(fp, vers, a, avtab_insertf, NULL);
|
if (rc) {
|
if (rc == SEPOL_ENOMEM)
|
ERR(fp->handle, "out of memory");
|
if (rc == SEPOL_EEXIST)
|
ERR(fp->handle, "duplicate entry");
|
ERR(fp->handle, "failed on entry %d of %u", i, nel);
|
goto bad;
|
}
|
}
|
|
return 0;
|
|
bad:
|
avtab_destroy(a);
|
return -1;
|
}
|
