593 lines
15 KiB
C
593 lines
15 KiB
C
#include <linux/version.h>
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#include "sepolicy.h"
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#include "../klog.h"
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// Invert is adding rules for auditdeny; in other cases, invert is removing rules
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#define strip_av(effect, invert) ((effect == AVTAB_AUDITDENY) == !invert)
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#define hash_for_each(node_ptr, n_slot, cur) \
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int i; \
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for (i = 0; i < n_slot; ++i) \
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for (cur = node_ptr[i]; cur; cur = cur->next)
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// htable is a struct instead of pointer above 5.8.0: https://elixir.bootlin.com/linux/v5.8-rc1/source/security/selinux/ss/symtab.h
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
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#define hashtab_for_each(htab, cur) hash_for_each (htab.htable, htab.size, cur)
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#else
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#define hashtab_for_each(htab, cur) hash_for_each (htab->htable, htab->size, cur)
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#endif
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// symtab_search is introduced on 5.9.0: https://elixir.bootlin.com/linux/v5.9-rc1/source/security/selinux/ss/symtab.h
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#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 9, 0)
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#define symtab_search(s, name) hashtab_search((s)->table, name)
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#endif
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#define avtab_for_each(avtab, cur) \
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hash_for_each (avtab.htable, avtab.nslot, cur) \
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;
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struct avtab_node *get_avtab_node(struct policydb *db, struct avtab_key *key,
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struct avtab_extended_perms *xperms)
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{
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struct avtab_node *node;
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/* AVTAB_XPERMS entries are not necessarily unique */
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if (key->specified & AVTAB_XPERMS) {
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bool match = false;
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node = avtab_search_node(&db->te_avtab, key);
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while (node) {
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if ((node->datum.u.xperms->specified ==
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xperms->specified) &&
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(node->datum.u.xperms->driver == xperms->driver)) {
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match = true;
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break;
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}
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node = avtab_search_node_next(node, key->specified);
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}
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if (!match)
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node = NULL;
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} else {
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node = avtab_search_node(&db->te_avtab, key);
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}
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if (!node) {
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struct avtab_datum avdatum = {};
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/*
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* AUDITDENY, aka DONTAUDIT, are &= assigned, versus |= for
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* others. Initialize the data accordingly.
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*/
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if (key->specified & AVTAB_XPERMS) {
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avdatum.u.xperms = xperms;
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} else {
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avdatum.u.data =
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key->specified == AVTAB_AUDITDENY ? ~0U : 0U;
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}
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/* this is used to get the node - insertion is actually unique */
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node = avtab_insert_nonunique(&db->te_avtab, key, &avdatum);
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int grow_size = sizeof(u16) * 4;
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if (key->specified & AVTAB_XPERMS) {
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grow_size += sizeof(u8);
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grow_size += sizeof(u8);
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grow_size += sizeof(u32) *
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ARRAY_SIZE(avdatum.u.xperms->perms.p);
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} else {
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grow_size += sizeof(u32) * 1;
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}
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db->len += grow_size;
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}
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return node;
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}
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bool add_rule(struct policydb *db, const char *s, const char *t, const char *c,
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const char *p, int effect, bool invert)
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{
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struct type_datum *src = NULL, *tgt = NULL;
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struct class_datum *cls = NULL;
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struct perm_datum *perm = NULL;
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if (s) {
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src = symtab_search(&db->p_types, s);
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if (src == NULL) {
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pr_info("source type %s does not exist\n", s);
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return false;
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}
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}
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if (t) {
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tgt = symtab_search(&db->p_types, t);
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if (tgt == NULL) {
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pr_info("target type %s does not exist\n", t);
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return false;
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}
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}
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if (c) {
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cls = symtab_search(&db->p_classes, c);
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if (cls == NULL) {
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pr_info("class %s does not exist\n", c);
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return false;
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}
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}
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if (p) {
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if (c == NULL) {
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pr_info("No class is specified, cannot add perm [%s] \n",
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p);
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return false;
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}
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perm = symtab_search(&cls->permissions, p);
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if (perm == NULL && cls->comdatum != NULL) {
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perm = symtab_search(&cls->comdatum->permissions, p);
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}
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if (perm == NULL) {
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pr_info("perm %s does not exist in class %s\n", p, c);
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return false;
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}
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}
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add_rule_raw(db, src, tgt, cls, perm, effect, invert);
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return true;
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}
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void add_rule_raw(struct policydb *db, struct type_datum *src,
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struct type_datum *tgt, struct class_datum *cls,
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struct perm_datum *perm, int effect, bool invert)
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{
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if (src == NULL) {
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struct hashtab_node *node;
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if (strip_av(effect, invert)) {
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hashtab_for_each(db->p_types.table, node)
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{
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add_rule_raw(db,
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(struct type_datum *)node->datum,
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tgt, cls, perm, effect, invert);
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};
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} else {
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hashtab_for_each(db->p_types.table, node)
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{
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struct type_datum *type =
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(struct type_datum *)(node->datum);
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if (type->attribute) {
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add_rule_raw(db, type, tgt, cls, perm,
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effect, invert);
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}
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};
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}
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} else if (tgt == NULL) {
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struct hashtab_node *node;
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if (strip_av(effect, invert)) {
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hashtab_for_each(db->p_types.table, node)
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{
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add_rule_raw(db, src,
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(struct type_datum *)node->datum,
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cls, perm, effect, invert);
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};
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} else {
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hashtab_for_each(db->p_types.table, node)
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{
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struct type_datum *type =
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(struct type_datum *)(node->datum);
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if (type->attribute) {
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add_rule_raw(db, src, type, cls, perm,
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effect, invert);
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}
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};
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}
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} else if (cls == NULL) {
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struct hashtab_node *node;
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hashtab_for_each(db->p_classes.table, node)
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{
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add_rule_raw(db, src, tgt,
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(struct class_datum *)node->datum, perm,
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effect, invert);
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}
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} else {
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struct avtab_key key;
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key.source_type = src->value;
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key.target_type = tgt->value;
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key.target_class = cls->value;
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key.specified = effect;
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struct avtab_node *node = get_avtab_node(db, &key, NULL);
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if (invert) {
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if (perm)
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node->datum.u.data &=
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~(1U << (perm->value - 1));
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else
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node->datum.u.data = 0U;
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} else {
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if (perm)
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node->datum.u.data |= 1U << (perm->value - 1);
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else
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node->datum.u.data = ~0U;
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}
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}
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}
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#define ioctl_driver(x) (x >> 8 & 0xFF)
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#define ioctl_func(x) (x & 0xFF)
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#define xperm_test(x, p) (1 & (p[x >> 5] >> (x & 0x1f)))
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#define xperm_set(x, p) (p[x >> 5] |= (1 << (x & 0x1f)))
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#define xperm_clear(x, p) (p[x >> 5] &= ~(1 << (x & 0x1f)))
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void add_xperm_rule_raw(struct policydb *db, struct type_datum *src,
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struct type_datum *tgt, struct class_datum *cls,
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uint16_t low, uint16_t high, int effect, bool invert)
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{
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if (src == NULL) {
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struct hashtab_node *node;
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hashtab_for_each(db->p_types.table, node)
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{
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struct type_datum *type =
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(struct type_datum *)(node->datum);
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if (type->attribute) {
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add_xperm_rule_raw(db, type, tgt, cls, low,
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high, effect, invert);
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}
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};
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} else if (tgt == NULL) {
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struct hashtab_node *node;
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hashtab_for_each(db->p_types.table, node)
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{
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struct type_datum *type =
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(struct type_datum *)(node->datum);
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if (type->attribute) {
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add_xperm_rule_raw(db, src, type, cls, low,
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high, effect, invert);
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}
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};
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} else if (cls == NULL) {
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struct hashtab_node *node;
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hashtab_for_each(db->p_classes.table, node)
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{
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add_xperm_rule_raw(db, src, tgt,
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(struct class_datum *)(node->datum),
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low, high, effect, invert);
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};
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} else {
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struct avtab_key key;
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key.source_type = src->value;
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key.target_type = tgt->value;
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key.target_class = cls->value;
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key.specified = effect;
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struct avtab_datum *datum;
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struct avtab_node *node;
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struct avtab_extended_perms xperms;
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memset(&xperms, 0, sizeof(xperms));
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if (ioctl_driver(low) != ioctl_driver(high)) {
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xperms.specified = AVTAB_XPERMS_IOCTLDRIVER;
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xperms.driver = 0;
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} else {
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xperms.specified = AVTAB_XPERMS_IOCTLFUNCTION;
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xperms.driver = ioctl_driver(low);
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}
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int i;
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if (xperms.specified == AVTAB_XPERMS_IOCTLDRIVER) {
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for (i = ioctl_driver(low); i <= ioctl_driver(high);
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++i) {
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if (invert)
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xperm_clear(i, xperms.perms.p);
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else
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xperm_set(i, xperms.perms.p);
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}
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} else {
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for (i = ioctl_func(low); i <= ioctl_func(high);
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++i) {
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if (invert)
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xperm_clear(i, xperms.perms.p);
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else
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xperm_set(i, xperms.perms.p);
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}
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}
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node = get_avtab_node(db, &key, &xperms);
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if (!node) {
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pr_warn("add_xperm_rule_raw cannot found node!\n");
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return;
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}
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datum = &node->datum;
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if (datum->u.xperms == NULL) {
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datum->u.xperms =
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(struct avtab_extended_perms *)(kmalloc(
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sizeof(xperms), GFP_KERNEL));
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if (!datum->u.xperms) {
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pr_err("alloc xperms failed\n");
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return;
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}
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memcpy(datum->u.xperms, &xperms, sizeof(xperms));
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}
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}
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}
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bool add_xperm_rule(struct policydb *db, const char *s, const char *t,
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const char *c, const char *range, int effect, bool invert)
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{
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struct type_datum *src = NULL, *tgt = NULL;
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struct class_datum *cls = NULL;
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if (s) {
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src = symtab_search(&db->p_types, s);
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if (src == NULL) {
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pr_info("source type %s does not exist\n", s);
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return false;
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}
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}
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if (t) {
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tgt = symtab_search(&db->p_types, t);
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if (tgt == NULL) {
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pr_info("target type %s does not exist\n", t);
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return false;
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}
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}
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if (c) {
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cls = symtab_search(&db->p_classes, c);
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if (cls == NULL) {
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pr_info("class %s does not exist\n", c);
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return false;
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}
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}
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u16 low, high;
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if (range) {
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if (strchr(range, '-')) {
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sscanf(range, "%hx-%hx", &low, &high);
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} else {
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sscanf(range, "%hx", &low);
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high = low;
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}
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} else {
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low = 0;
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high = 0xFFFF;
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}
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add_xperm_rule_raw(db, src, tgt, cls, low, high, effect, invert);
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return true;
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}
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bool add_type_rule(struct policydb *db, const char *s, const char *t,
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const char *c, const char *d, int effect)
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{
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struct type_datum *src, *tgt, *def;
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struct class_datum *cls;
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src = symtab_search(&db->p_types, s);
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if (src == NULL) {
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pr_info("source type %s does not exist\n", s);
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return false;
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}
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tgt = symtab_search(&db->p_types, t);
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if (tgt == NULL) {
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pr_info("target type %s does not exist\n", t);
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return false;
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}
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cls = symtab_search(&db->p_classes, c);
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if (cls == NULL) {
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pr_info("class %s does not exist\n", c);
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return false;
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}
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def = symtab_search(&db->p_types, d);
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if (def == NULL) {
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pr_info("default type %s does not exist\n", d);
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return false;
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}
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struct avtab_key key;
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key.source_type = src->value;
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key.target_type = tgt->value;
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key.target_class = cls->value;
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key.specified = effect;
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struct avtab_node *node = get_avtab_node(db, &key, NULL);
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node->datum.u.data = def->value;
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return true;
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}
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bool add_filename_trans(const char *s, const char *t, const char *c,
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const char *d, const char *o)
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{
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return false;
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}
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bool add_genfscon(const char *fs_name, const char *path, const char *context)
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{
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return false;
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}
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bool add_type(struct policydb *db, const char *type_name, bool attr)
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{
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return false;
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}
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bool set_type_state(struct policydb *db, const char *type_name, bool permissive)
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{
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struct type_datum *type;
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if (type_name == NULL) {
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struct hashtab_node *node;
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hashtab_for_each(db->p_types.table, node)
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{
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type = (struct type_datum *)(node->datum);
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if (ebitmap_set_bit(&db->permissive_map, type->value,
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permissive))
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pr_info("Could not set bit in permissive map\n");
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};
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} else {
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type = (struct type_datum *)symtab_search(&db->p_types,
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type_name);
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if (type == NULL) {
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pr_info("type %s does not exist\n", type_name);
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return false;
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}
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if (ebitmap_set_bit(&db->permissive_map, type->value,
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permissive)) {
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pr_info("Could not set bit in permissive map\n");
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return false;
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}
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}
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return true;
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}
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void add_typeattribute_raw(struct policydb *db, struct type_datum *type,
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struct type_datum *attr)
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{
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 1, 0)
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struct ebitmap *sattr = &db->type_attr_map_array[type->value - 1];
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#else
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struct ebitmap *sattr = flex_array_get(db->type_attr_map_array, type->value -1);
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#endif
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ebitmap_set_bit(sattr, attr->value - 1, 1);
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struct hashtab_node *node;
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struct constraint_node *n;
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struct constraint_expr *e;
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hashtab_for_each(db->p_classes.table, node)
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{
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struct class_datum *cls = (struct class_datum *)(node->datum);
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for (n = cls->constraints; n; n = n->next) {
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for (e = n->expr; e; e = e->next) {
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if (e->expr_type == CEXPR_NAMES &&
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ebitmap_get_bit(&e->type_names->types,
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attr->value - 1)) {
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ebitmap_set_bit(&e->names,
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type->value - 1, 1);
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}
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}
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}
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};
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}
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bool add_typeattribute(struct policydb *db, const char *type, const char *attr)
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{
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struct type_datum *type_d = symtab_search(&db->p_types, type);
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if (type_d == NULL) {
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pr_info("type %s does not exist\n", type);
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return false;
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} else if (type_d->attribute) {
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pr_info("type %s is an attribute\n", attr);
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return false;
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}
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struct type_datum *attr_d = symtab_search(&db->p_types, attr);
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if (attr_d == NULL) {
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pr_info("attribute %s does not exist\n", type);
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return false;
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} else if (!attr_d->attribute) {
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pr_info("type %s is not an attribute \n", attr);
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return false;
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}
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add_typeattribute_raw(db, type_d, attr_d);
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return true;
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}
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// Operation on types
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bool type(struct policydb *db, const char *name, const char *attr)
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{
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return add_type(db, name, false) && add_typeattribute(db, name, attr);
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}
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bool attribute(struct policydb *db, const char *name)
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{
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return add_type(db, name, true);
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}
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|
|
|
bool permissive(struct policydb *db, const char *type)
|
|
{
|
|
return set_type_state(db, type, true);
|
|
}
|
|
|
|
bool enforce(struct policydb *db, const char *type)
|
|
{
|
|
return set_type_state(db, type, false);
|
|
}
|
|
|
|
bool typeattribute(struct policydb *db, const char *type, const char *attr)
|
|
{
|
|
return add_typeattribute(db, type, attr);
|
|
}
|
|
|
|
bool exists(struct policydb *db, const char *type)
|
|
{
|
|
return symtab_search(&db->p_types, type) != NULL;
|
|
}
|
|
|
|
// Access vector rules
|
|
bool allow(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *perm)
|
|
{
|
|
return add_rule(db, src, tgt, cls, perm, AVTAB_ALLOWED, false);
|
|
}
|
|
|
|
bool deny(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *perm)
|
|
{
|
|
return add_rule(db, src, tgt, cls, perm, AVTAB_ALLOWED, true);
|
|
}
|
|
|
|
bool auditallow(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *perm)
|
|
{
|
|
return add_rule(db, src, tgt, cls, perm, AVTAB_AUDITALLOW, false);
|
|
}
|
|
bool dontaudit(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *perm)
|
|
{
|
|
return add_rule(db, src, tgt, cls, perm, AVTAB_AUDITDENY, true);
|
|
}
|
|
|
|
// Extended permissions access vector rules
|
|
bool allowxperm(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *range)
|
|
{
|
|
return add_xperm_rule(db, src, tgt, cls, range, AVTAB_XPERMS_ALLOWED,
|
|
false);
|
|
}
|
|
|
|
bool auditallowxperm(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *range)
|
|
{
|
|
return add_xperm_rule(db, src, tgt, cls, range, AVTAB_XPERMS_AUDITALLOW,
|
|
false);
|
|
}
|
|
|
|
bool dontauditxperm(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *range)
|
|
{
|
|
return add_xperm_rule(db, src, tgt, cls, range, AVTAB_XPERMS_DONTAUDIT,
|
|
false);
|
|
}
|
|
|
|
// Type rules
|
|
bool type_transition(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *def, const char *obj)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
bool type_change(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *def)
|
|
{
|
|
return false;
|
|
}
|
|
bool type_member(struct policydb *db, const char *src, const char *tgt,
|
|
const char *cls, const char *def)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
// File system labeling
|
|
bool genfscon(struct policydb *db, const char *fs_name, const char *path,
|
|
const char *ctx)
|
|
{
|
|
return false;
|
|
} |