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linux/security/selinux/ss/conditional.c
Eric Paris 7c2b240ef2 SELinux: conditional.c whitespace, syntax, and static declaraction cleanups
This patch changes conditional.c to fix whitespace and syntax issues.  Things that
are fixed may include (does not not have to include)

whitespace at end of lines
spaces followed by tabs
spaces used instead of tabs
spacing around parenthesis
locateion of { around struct and else clauses
location of * in pointer declarations
removal of initialization of static data to keep it in the right section
useless {} in if statemetns
useless checking for NULL before kfree
fixing of the indentation depth of switch statements
and any number of other things I forgot to mention

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-21 19:07:31 +10:00

508 lines
11 KiB
C

/* Authors: Karl MacMillan <kmacmillan@tresys.com>
* Frank Mayer <mayerf@tresys.com>
*
* Copyright (C) 2003 - 2004 Tresys Technology, LLC
* 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.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <asm/semaphore.h>
#include <linux/slab.h>
#include "security.h"
#include "conditional.h"
/*
* cond_evaluate_expr evaluates a conditional expr
* in reverse polish notation. It returns true (1), false (0),
* or undefined (-1). Undefined occurs when the expression
* exceeds the stack depth of COND_EXPR_MAXDEPTH.
*/
static int cond_evaluate_expr(struct policydb *p, struct cond_expr *expr)
{
struct cond_expr *cur;
int s[COND_EXPR_MAXDEPTH];
int sp = -1;
for (cur = expr; cur != NULL; cur = cur->next) {
switch (cur->expr_type) {
case COND_BOOL:
if (sp == (COND_EXPR_MAXDEPTH - 1))
return -1;
sp++;
s[sp] = p->bool_val_to_struct[cur->bool - 1]->state;
break;
case COND_NOT:
if (sp < 0)
return -1;
s[sp] = !s[sp];
break;
case COND_OR:
if (sp < 1)
return -1;
sp--;
s[sp] |= s[sp + 1];
break;
case COND_AND:
if (sp < 1)
return -1;
sp--;
s[sp] &= s[sp + 1];
break;
case COND_XOR:
if (sp < 1)
return -1;
sp--;
s[sp] ^= s[sp + 1];
break;
case COND_EQ:
if (sp < 1)
return -1;
sp--;
s[sp] = (s[sp] == s[sp + 1]);
break;
case COND_NEQ:
if (sp < 1)
return -1;
sp--;
s[sp] = (s[sp] != s[sp + 1]);
break;
default:
return -1;
}
}
return s[0];
}
/*
* evaluate_cond_node evaluates the conditional stored in
* a struct cond_node and if the result is different than the
* current state of the node it sets the rules in the true/false
* list appropriately. If the result of the expression is undefined
* all of the rules are disabled for safety.
*/
int evaluate_cond_node(struct policydb *p, struct cond_node *node)
{
int new_state;
struct cond_av_list *cur;
new_state = cond_evaluate_expr(p, node->expr);
if (new_state != node->cur_state) {
node->cur_state = new_state;
if (new_state == -1)
printk(KERN_ERR "SELinux: expression result was undefined - disabling all rules.\n");
/* turn the rules on or off */
for (cur = node->true_list; cur != NULL; cur = cur->next) {
if (new_state <= 0)
cur->node->key.specified &= ~AVTAB_ENABLED;
else
cur->node->key.specified |= AVTAB_ENABLED;
}
for (cur = node->false_list; cur != NULL; cur = cur->next) {
/* -1 or 1 */
if (new_state)
cur->node->key.specified &= ~AVTAB_ENABLED;
else
cur->node->key.specified |= AVTAB_ENABLED;
}
}
return 0;
}
int cond_policydb_init(struct policydb *p)
{
p->bool_val_to_struct = NULL;
p->cond_list = NULL;
if (avtab_init(&p->te_cond_avtab))
return -1;
return 0;
}
static void cond_av_list_destroy(struct cond_av_list *list)
{
struct cond_av_list *cur, *next;
for (cur = list; cur != NULL; cur = next) {
next = cur->next;
/* the avtab_ptr_t node is destroy by the avtab */
kfree(cur);
}
}
static void cond_node_destroy(struct cond_node *node)
{
struct cond_expr *cur_expr, *next_expr;
for (cur_expr = node->expr; cur_expr != NULL; cur_expr = next_expr) {
next_expr = cur_expr->next;
kfree(cur_expr);
}
cond_av_list_destroy(node->true_list);
cond_av_list_destroy(node->false_list);
kfree(node);
}
static void cond_list_destroy(struct cond_node *list)
{
struct cond_node *next, *cur;
if (list == NULL)
return;
for (cur = list; cur != NULL; cur = next) {
next = cur->next;
cond_node_destroy(cur);
}
}
void cond_policydb_destroy(struct policydb *p)
{
kfree(p->bool_val_to_struct);
avtab_destroy(&p->te_cond_avtab);
cond_list_destroy(p->cond_list);
}
int cond_init_bool_indexes(struct policydb *p)
{
kfree(p->bool_val_to_struct);
p->bool_val_to_struct = (struct cond_bool_datum **)
kmalloc(p->p_bools.nprim * sizeof(struct cond_bool_datum *), GFP_KERNEL);
if (!p->bool_val_to_struct)
return -1;
return 0;
}
int cond_destroy_bool(void *key, void *datum, void *p)
{
kfree(key);
kfree(datum);
return 0;
}
int cond_index_bool(void *key, void *datum, void *datap)
{
struct policydb *p;
struct cond_bool_datum *booldatum;
booldatum = datum;
p = datap;
if (!booldatum->value || booldatum->value > p->p_bools.nprim)
return -EINVAL;
p->p_bool_val_to_name[booldatum->value - 1] = key;
p->bool_val_to_struct[booldatum->value - 1] = booldatum;
return 0;
}
static int bool_isvalid(struct cond_bool_datum *b)
{
if (!(b->state == 0 || b->state == 1))
return 0;
return 1;
}
int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp)
{
char *key = NULL;
struct cond_bool_datum *booldatum;
__le32 buf[3];
u32 len;
int rc;
booldatum = kzalloc(sizeof(struct cond_bool_datum), GFP_KERNEL);
if (!booldatum)
return -1;
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
goto err;
booldatum->value = le32_to_cpu(buf[0]);
booldatum->state = le32_to_cpu(buf[1]);
if (!bool_isvalid(booldatum))
goto err;
len = le32_to_cpu(buf[2]);
key = kmalloc(len + 1, GFP_KERNEL);
if (!key)
goto err;
rc = next_entry(key, fp, len);
if (rc < 0)
goto err;
key[len] = 0;
if (hashtab_insert(h, key, booldatum))
goto err;
return 0;
err:
cond_destroy_bool(key, booldatum, NULL);
return -1;
}
struct cond_insertf_data {
struct policydb *p;
struct cond_av_list *other;
struct cond_av_list *head;
struct cond_av_list *tail;
};
static int cond_insertf(struct avtab *a, struct avtab_key *k, struct avtab_datum *d, void *ptr)
{
struct cond_insertf_data *data = ptr;
struct policydb *p = data->p;
struct cond_av_list *other = data->other, *list, *cur;
struct avtab_node *node_ptr;
u8 found;
/*
* For type rules we have to make certain there aren't any
* conflicting rules by searching the te_avtab and the
* cond_te_avtab.
*/
if (k->specified & AVTAB_TYPE) {
if (avtab_search(&p->te_avtab, k)) {
printk("SELinux: type rule already exists outside of a conditional.");
goto err;
}
/*
* If we are reading the false list other will be a pointer to
* the true list. We can have duplicate entries if there is only
* 1 other entry and it is in our true list.
*
* If we are reading the true list (other == NULL) there shouldn't
* be any other entries.
*/
if (other) {
node_ptr = avtab_search_node(&p->te_cond_avtab, k);
if (node_ptr) {
if (avtab_search_node_next(node_ptr, k->specified)) {
printk("SELinux: too many conflicting type rules.");
goto err;
}
found = 0;
for (cur = other; cur != NULL; cur = cur->next) {
if (cur->node == node_ptr) {
found = 1;
break;
}
}
if (!found) {
printk("SELinux: conflicting type rules.\n");
goto err;
}
}
} else {
if (avtab_search(&p->te_cond_avtab, k)) {
printk("SELinux: conflicting type rules when adding type rule for true.\n");
goto err;
}
}
}
node_ptr = avtab_insert_nonunique(&p->te_cond_avtab, k, d);
if (!node_ptr) {
printk("SELinux: could not insert rule.");
goto err;
}
list = kzalloc(sizeof(struct cond_av_list), GFP_KERNEL);
if (!list)
goto err;
list->node = node_ptr;
if (!data->head)
data->head = list;
else
data->tail->next = list;
data->tail = list;
return 0;
err:
cond_av_list_destroy(data->head);
data->head = NULL;
return -1;
}
static int cond_read_av_list(struct policydb *p, void *fp, struct cond_av_list **ret_list, struct cond_av_list *other)
{
int i, rc;
__le32 buf[1];
u32 len;
struct cond_insertf_data data;
*ret_list = NULL;
len = 0;
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0)
return -1;
len = le32_to_cpu(buf[0]);
if (len == 0)
return 0;
data.p = p;
data.other = other;
data.head = NULL;
data.tail = NULL;
for (i = 0; i < len; i++) {
rc = avtab_read_item(&p->te_cond_avtab, fp, p, cond_insertf,
&data);
if (rc)
return rc;
}
*ret_list = data.head;
return 0;
}
static int expr_isvalid(struct policydb *p, struct cond_expr *expr)
{
if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) {
printk("SELinux: conditional expressions uses unknown operator.\n");
return 0;
}
if (expr->bool > p->p_bools.nprim) {
printk("SELinux: conditional expressions uses unknown bool.\n");
return 0;
}
return 1;
}
static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
{
__le32 buf[2];
u32 len, i;
int rc;
struct cond_expr *expr = NULL, *last = NULL;
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0)
return -1;
node->cur_state = le32_to_cpu(buf[0]);
len = 0;
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0)
return -1;
/* expr */
len = le32_to_cpu(buf[0]);
for (i = 0; i < len; i++) {
rc = next_entry(buf, fp, sizeof(u32) * 2);
if (rc < 0)
goto err;
expr = kzalloc(sizeof(struct cond_expr), GFP_KERNEL);
if (!expr)
goto err;
expr->expr_type = le32_to_cpu(buf[0]);
expr->bool = le32_to_cpu(buf[1]);
if (!expr_isvalid(p, expr)) {
kfree(expr);
goto err;
}
if (i == 0)
node->expr = expr;
else
last->next = expr;
last = expr;
}
if (cond_read_av_list(p, fp, &node->true_list, NULL) != 0)
goto err;
if (cond_read_av_list(p, fp, &node->false_list, node->true_list) != 0)
goto err;
return 0;
err:
cond_node_destroy(node);
return -1;
}
int cond_read_list(struct policydb *p, void *fp)
{
struct cond_node *node, *last = NULL;
__le32 buf[1];
u32 i, len;
int rc;
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
return -1;
len = le32_to_cpu(buf[0]);
rc = avtab_alloc(&(p->te_cond_avtab), p->te_avtab.nel);
if (rc)
goto err;
for (i = 0; i < len; i++) {
node = kzalloc(sizeof(struct cond_node), GFP_KERNEL);
if (!node)
goto err;
if (cond_read_node(p, node, fp) != 0)
goto err;
if (i == 0)
p->cond_list = node;
else
last->next = node;
last = node;
}
return 0;
err:
cond_list_destroy(p->cond_list);
p->cond_list = NULL;
return -1;
}
/* Determine whether additional permissions are granted by the conditional
* av table, and if so, add them to the result
*/
void cond_compute_av(struct avtab *ctab, struct avtab_key *key, struct av_decision *avd)
{
struct avtab_node *node;
if (!ctab || !key || !avd)
return;
for (node = avtab_search_node(ctab, key); node != NULL;
node = avtab_search_node_next(node, key->specified)) {
if ((u16)(AVTAB_ALLOWED|AVTAB_ENABLED) ==
(node->key.specified & (AVTAB_ALLOWED|AVTAB_ENABLED)))
avd->allowed |= node->datum.data;
if ((u16)(AVTAB_AUDITDENY|AVTAB_ENABLED) ==
(node->key.specified & (AVTAB_AUDITDENY|AVTAB_ENABLED)))
/* Since a '0' in an auditdeny mask represents a
* permission we do NOT want to audit (dontaudit), we use
* the '&' operand to ensure that all '0's in the mask
* are retained (much unlike the allow and auditallow cases).
*/
avd->auditdeny &= node->datum.data;
if ((u16)(AVTAB_AUDITALLOW|AVTAB_ENABLED) ==
(node->key.specified & (AVTAB_AUDITALLOW|AVTAB_ENABLED)))
avd->auditallow |= node->datum.data;
}
return;
}