diff options
Diffstat (limited to 'ANDROID_3.4.5/security/selinux/ss/conditional.c')
-rw-r--r-- | ANDROID_3.4.5/security/selinux/ss/conditional.c | 648 |
1 files changed, 0 insertions, 648 deletions
diff --git a/ANDROID_3.4.5/security/selinux/ss/conditional.c b/ANDROID_3.4.5/security/selinux/ss/conditional.c deleted file mode 100644 index 377d148e..00000000 --- a/ANDROID_3.4.5/security/selinux/ss/conditional.c +++ /dev/null @@ -1,648 +0,0 @@ -/* 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 <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; 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; 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; 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) -{ - int rc; - - p->bool_val_to_struct = NULL; - p->cond_list = NULL; - - rc = avtab_init(&p->te_cond_avtab); - if (rc) - return rc; - - return 0; -} - -static void cond_av_list_destroy(struct cond_av_list *list) -{ - struct cond_av_list *cur, *next; - for (cur = list; cur; 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; 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; 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 = - kmalloc(p->p_bools.nprim * sizeof(struct cond_bool_datum *), GFP_KERNEL); - if (!p->bool_val_to_struct) - return -ENOMEM; - 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; - struct flex_array *fa; - - booldatum = datum; - p = datap; - - if (!booldatum->value || booldatum->value > p->p_bools.nprim) - return -EINVAL; - - fa = p->sym_val_to_name[SYM_BOOLS]; - if (flex_array_put_ptr(fa, booldatum->value - 1, key, - GFP_KERNEL | __GFP_ZERO)) - BUG(); - 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 -ENOMEM; - - rc = next_entry(buf, fp, sizeof buf); - if (rc) - goto err; - - booldatum->value = le32_to_cpu(buf[0]); - booldatum->state = le32_to_cpu(buf[1]); - - rc = -EINVAL; - if (!bool_isvalid(booldatum)) - goto err; - - len = le32_to_cpu(buf[2]); - - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_KERNEL); - if (!key) - goto err; - rc = next_entry(key, fp, len); - if (rc) - goto err; - key[len] = '\0'; - rc = hashtab_insert(h, key, booldatum); - if (rc) - goto err; - - return 0; -err: - cond_destroy_bool(key, booldatum, NULL); - return rc; -} - -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; - int rc = -EINVAL; - - /* - * 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(KERN_ERR "SELinux: type rule already exists outside of a conditional.\n"); - 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(KERN_ERR "SELinux: too many conflicting type rules.\n"); - goto err; - } - found = 0; - for (cur = other; cur; cur = cur->next) { - if (cur->node == node_ptr) { - found = 1; - break; - } - } - if (!found) { - printk(KERN_ERR "SELinux: conflicting type rules.\n"); - goto err; - } - } - } else { - if (avtab_search(&p->te_cond_avtab, k)) { - printk(KERN_ERR "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(KERN_ERR "SELinux: could not insert rule.\n"); - rc = -ENOMEM; - goto err; - } - - list = kzalloc(sizeof(struct cond_av_list), GFP_KERNEL); - if (!list) { - rc = -ENOMEM; - 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 rc; -} - -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) - return rc; - - 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(KERN_ERR "SELinux: conditional expressions uses unknown operator.\n"); - return 0; - } - - if (expr->bool > p->p_bools.nprim) { - printk(KERN_ERR "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) - return rc; - - node->cur_state = le32_to_cpu(buf[0]); - - len = 0; - rc = next_entry(buf, fp, sizeof(u32)); - if (rc) - return rc; - - /* expr */ - len = le32_to_cpu(buf[0]); - - for (i = 0; i < len; i++) { - rc = next_entry(buf, fp, sizeof(u32) * 2); - if (rc) - goto err; - - rc = -ENOMEM; - 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)) { - rc = -EINVAL; - kfree(expr); - goto err; - } - - if (i == 0) - node->expr = expr; - else - last->next = expr; - last = expr; - } - - rc = cond_read_av_list(p, fp, &node->true_list, NULL); - if (rc) - goto err; - rc = cond_read_av_list(p, fp, &node->false_list, node->true_list); - if (rc) - goto err; - return 0; -err: - cond_node_destroy(node); - return rc; -} - -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) - return rc; - - 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++) { - rc = -ENOMEM; - node = kzalloc(sizeof(struct cond_node), GFP_KERNEL); - if (!node) - goto err; - - rc = cond_read_node(p, node, fp); - if (rc) - 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 rc; -} - -int cond_write_bool(void *vkey, void *datum, void *ptr) -{ - char *key = vkey; - struct cond_bool_datum *booldatum = datum; - struct policy_data *pd = ptr; - void *fp = pd->fp; - __le32 buf[3]; - u32 len; - int rc; - - len = strlen(key); - buf[0] = cpu_to_le32(booldatum->value); - buf[1] = cpu_to_le32(booldatum->state); - buf[2] = cpu_to_le32(len); - rc = put_entry(buf, sizeof(u32), 3, fp); - if (rc) - return rc; - rc = put_entry(key, 1, len, fp); - if (rc) - return rc; - return 0; -} - -/* - * cond_write_cond_av_list doesn't write out the av_list nodes. - * Instead it writes out the key/value pairs from the avtab. This - * is necessary because there is no way to uniquely identifying rules - * in the avtab so it is not possible to associate individual rules - * in the avtab with a conditional without saving them as part of - * the conditional. This means that the avtab with the conditional - * rules will not be saved but will be rebuilt on policy load. - */ -static int cond_write_av_list(struct policydb *p, - struct cond_av_list *list, struct policy_file *fp) -{ - __le32 buf[1]; - struct cond_av_list *cur_list; - u32 len; - int rc; - - len = 0; - for (cur_list = list; cur_list != NULL; cur_list = cur_list->next) - len++; - - buf[0] = cpu_to_le32(len); - rc = put_entry(buf, sizeof(u32), 1, fp); - if (rc) - return rc; - - if (len == 0) - return 0; - - for (cur_list = list; cur_list != NULL; cur_list = cur_list->next) { - rc = avtab_write_item(p, cur_list->node, fp); - if (rc) - return rc; - } - - return 0; -} - -static int cond_write_node(struct policydb *p, struct cond_node *node, - struct policy_file *fp) -{ - struct cond_expr *cur_expr; - __le32 buf[2]; - int rc; - u32 len = 0; - - buf[0] = cpu_to_le32(node->cur_state); - rc = put_entry(buf, sizeof(u32), 1, fp); - if (rc) - return rc; - - for (cur_expr = node->expr; cur_expr != NULL; cur_expr = cur_expr->next) - len++; - - buf[0] = cpu_to_le32(len); - rc = put_entry(buf, sizeof(u32), 1, fp); - if (rc) - return rc; - - for (cur_expr = node->expr; cur_expr != NULL; cur_expr = cur_expr->next) { - buf[0] = cpu_to_le32(cur_expr->expr_type); - buf[1] = cpu_to_le32(cur_expr->bool); - rc = put_entry(buf, sizeof(u32), 2, fp); - if (rc) - return rc; - } - - rc = cond_write_av_list(p, node->true_list, fp); - if (rc) - return rc; - rc = cond_write_av_list(p, node->false_list, fp); - if (rc) - return rc; - - return 0; -} - -int cond_write_list(struct policydb *p, struct cond_node *list, void *fp) -{ - struct cond_node *cur; - u32 len; - __le32 buf[1]; - int rc; - - len = 0; - for (cur = list; cur != NULL; cur = cur->next) - len++; - buf[0] = cpu_to_le32(len); - rc = put_entry(buf, sizeof(u32), 1, fp); - if (rc) - return rc; - - for (cur = list; cur != NULL; cur = cur->next) { - rc = cond_write_node(p, cur, fp); - if (rc) - return rc; - } - - return 0; -} -/* 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; - 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; -} |