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-rw-r--r--security/selinux/ss/avtab.c556
1 files changed, 556 insertions, 0 deletions
diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
new file mode 100644
index 00000000..a3dd9faa
--- /dev/null
+++ b/security/selinux/ss/avtab.c
@@ -0,0 +1,556 @@
+/*
+ * Implementation of the access vector table type.
+ *
+ * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
+ */
+
+/* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
+ *
+ * Added conditional policy language extensions
+ *
+ * Copyright (C) 2003 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.
+ *
+ * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
+ * Tuned number of hash slots for avtab to reduce memory usage
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include "avtab.h"
+#include "policydb.h"
+
+static struct kmem_cache *avtab_node_cachep;
+
+static inline int avtab_hash(struct avtab_key *keyp, u16 mask)
+{
+ return ((keyp->target_class + (keyp->target_type << 2) +
+ (keyp->source_type << 9)) & mask);
+}
+
+static struct avtab_node*
+avtab_insert_node(struct avtab *h, int hvalue,
+ struct avtab_node *prev, struct avtab_node *cur,
+ struct avtab_key *key, struct avtab_datum *datum)
+{
+ struct avtab_node *newnode;
+ newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL);
+ if (newnode == NULL)
+ return NULL;
+ newnode->key = *key;
+ 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;
+}
+
+static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
+{
+ int hvalue;
+ struct avtab_node *prev, *cur, *newnode;
+ u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
+
+ if (!h || !h->htable)
+ return -EINVAL;
+
+ 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))
+ return -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, cur, key, datum);
+ if (!newnode)
+ return -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.
+ */
+struct avtab_node *
+avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
+{
+ int hvalue;
+ struct avtab_node *prev, *cur;
+ u16 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;
+ }
+ return avtab_insert_node(h, hvalue, prev, cur, key, datum);
+}
+
+struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
+{
+ int hvalue;
+ struct avtab_node *cur;
+ u16 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()
+ */
+struct avtab_node*
+avtab_search_node(struct avtab *h, struct avtab_key *key)
+{
+ int hvalue;
+ struct avtab_node *cur;
+ u16 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;
+}
+
+struct avtab_node*
+avtab_search_node_next(struct avtab_node *node, int specified)
+{
+ struct avtab_node *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(struct avtab *h)
+{
+ int i;
+ struct avtab_node *cur, *temp;
+
+ if (!h || !h->htable)
+ return;
+
+ for (i = 0; i < h->nslot; i++) {
+ cur = h->htable[i];
+ while (cur) {
+ temp = cur;
+ cur = cur->next;
+ kmem_cache_free(avtab_node_cachep, temp);
+ }
+ h->htable[i] = NULL;
+ }
+ kfree(h->htable);
+ h->htable = NULL;
+ h->nslot = 0;
+ h->mask = 0;
+}
+
+int avtab_init(struct avtab *h)
+{
+ h->htable = NULL;
+ h->nel = 0;
+ return 0;
+}
+
+int avtab_alloc(struct avtab *h, u32 nrules)
+{
+ u16 mask = 0;
+ u32 shift = 0;
+ u32 work = nrules;
+ u32 nslot = 0;
+
+ if (nrules == 0)
+ goto avtab_alloc_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 = kcalloc(nslot, sizeof(*(h->htable)), GFP_KERNEL);
+ if (!h->htable)
+ return -ENOMEM;
+
+ avtab_alloc_out:
+ h->nel = 0;
+ h->nslot = nslot;
+ h->mask = mask;
+ printk(KERN_DEBUG "SELinux: %d avtab hash slots, %d rules.\n",
+ h->nslot, nrules);
+ return 0;
+}
+
+void avtab_hash_eval(struct avtab *h, char *tag)
+{
+ int i, chain_len, slots_used, max_chain_len;
+ unsigned long long chain2_len_sum;
+ struct avtab_node *cur;
+
+ slots_used = 0;
+ max_chain_len = 0;
+ chain2_len_sum = 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;
+ chain2_len_sum += chain_len * chain_len;
+ }
+ }
+
+ printk(KERN_DEBUG "SELinux: %s: %d entries and %d/%d buckets used, "
+ "longest chain length %d sum of chain length^2 %llu\n",
+ tag, h->nel, slots_used, h->nslot, max_chain_len,
+ chain2_len_sum);
+}
+
+static uint16_t spec_order[] = {
+ AVTAB_ALLOWED,
+ AVTAB_AUDITDENY,
+ AVTAB_AUDITALLOW,
+ AVTAB_TRANSITION,
+ AVTAB_CHANGE,
+ AVTAB_MEMBER
+};
+
+int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol,
+ int (*insertf)(struct avtab *a, struct avtab_key *k,
+ struct avtab_datum *d, void *p),
+ void *p)
+{
+ __le16 buf16[4];
+ u16 enabled;
+ __le32 buf32[7];
+ u32 items, items2, val, vers = pol->policyvers;
+ struct avtab_key key;
+ struct avtab_datum datum;
+ int i, rc;
+ unsigned set;
+
+ memset(&key, 0, sizeof(struct avtab_key));
+ memset(&datum, 0, sizeof(struct avtab_datum));
+
+ if (vers < POLICYDB_VERSION_AVTAB) {
+ rc = next_entry(buf32, fp, sizeof(u32));
+ if (rc) {
+ printk(KERN_ERR "SELinux: avtab: truncated entry\n");
+ return rc;
+ }
+ items2 = le32_to_cpu(buf32[0]);
+ if (items2 > ARRAY_SIZE(buf32)) {
+ printk(KERN_ERR "SELinux: avtab: entry overflow\n");
+ return -EINVAL;
+
+ }
+ rc = next_entry(buf32, fp, sizeof(u32)*items2);
+ if (rc) {
+ printk(KERN_ERR "SELinux: avtab: truncated entry\n");
+ return rc;
+ }
+ items = 0;
+
+ val = le32_to_cpu(buf32[items++]);
+ key.source_type = (u16)val;
+ if (key.source_type != val) {
+ printk(KERN_ERR "SELinux: avtab: truncated source type\n");
+ return -EINVAL;
+ }
+ val = le32_to_cpu(buf32[items++]);
+ key.target_type = (u16)val;
+ if (key.target_type != val) {
+ printk(KERN_ERR "SELinux: avtab: truncated target type\n");
+ return -EINVAL;
+ }
+ val = le32_to_cpu(buf32[items++]);
+ key.target_class = (u16)val;
+ if (key.target_class != val) {
+ printk(KERN_ERR "SELinux: avtab: truncated target class\n");
+ return -EINVAL;
+ }
+
+ val = le32_to_cpu(buf32[items++]);
+ enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0;
+
+ if (!(val & (AVTAB_AV | AVTAB_TYPE))) {
+ printk(KERN_ERR "SELinux: avtab: null entry\n");
+ return -EINVAL;
+ }
+ if ((val & AVTAB_AV) &&
+ (val & AVTAB_TYPE)) {
+ printk(KERN_ERR "SELinux: avtab: entry has both access vectors and types\n");
+ return -EINVAL;
+ }
+
+ 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) {
+ printk(KERN_ERR "SELinux: avtab: entry only had %d items, expected %d\n", items2, items);
+ return -EINVAL;
+ }
+ return 0;
+ }
+
+ rc = next_entry(buf16, fp, sizeof(u16)*4);
+ if (rc) {
+ printk(KERN_ERR "SELinux: avtab: truncated entry\n");
+ return rc;
+ }
+
+ 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++]);
+
+ if (!policydb_type_isvalid(pol, key.source_type) ||
+ !policydb_type_isvalid(pol, key.target_type) ||
+ !policydb_class_isvalid(pol, key.target_class)) {
+ printk(KERN_ERR "SELinux: avtab: invalid type or class\n");
+ return -EINVAL;
+ }
+
+ set = 0;
+ for (i = 0; i < ARRAY_SIZE(spec_order); i++) {
+ if (key.specified & spec_order[i])
+ set++;
+ }
+ if (!set || set > 1) {
+ printk(KERN_ERR "SELinux: avtab: more than one specifier\n");
+ return -EINVAL;
+ }
+
+ rc = next_entry(buf32, fp, sizeof(u32));
+ if (rc) {
+ printk(KERN_ERR "SELinux: avtab: truncated entry\n");
+ return rc;
+ }
+ datum.data = le32_to_cpu(*buf32);
+ if ((key.specified & AVTAB_TYPE) &&
+ !policydb_type_isvalid(pol, datum.data)) {
+ printk(KERN_ERR "SELinux: avtab: invalid type\n");
+ return -EINVAL;
+ }
+ return insertf(a, &key, &datum, p);
+}
+
+static int avtab_insertf(struct avtab *a, struct avtab_key *k,
+ struct avtab_datum *d, void *p)
+{
+ return avtab_insert(a, k, d);
+}
+
+int avtab_read(struct avtab *a, void *fp, struct policydb *pol)
+{
+ int rc;
+ __le32 buf[1];
+ u32 nel, i;
+
+
+ rc = next_entry(buf, fp, sizeof(u32));
+ if (rc < 0) {
+ printk(KERN_ERR "SELinux: avtab: truncated table\n");
+ goto bad;
+ }
+ nel = le32_to_cpu(buf[0]);
+ if (!nel) {
+ printk(KERN_ERR "SELinux: avtab: table is empty\n");
+ rc = -EINVAL;
+ goto bad;
+ }
+
+ rc = avtab_alloc(a, nel);
+ if (rc)
+ goto bad;
+
+ for (i = 0; i < nel; i++) {
+ rc = avtab_read_item(a, fp, pol, avtab_insertf, NULL);
+ if (rc) {
+ if (rc == -ENOMEM)
+ printk(KERN_ERR "SELinux: avtab: out of memory\n");
+ else if (rc == -EEXIST)
+ printk(KERN_ERR "SELinux: avtab: duplicate entry\n");
+
+ goto bad;
+ }
+ }
+
+ rc = 0;
+out:
+ return rc;
+
+bad:
+ avtab_destroy(a);
+ goto out;
+}
+
+int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp)
+{
+ __le16 buf16[4];
+ __le32 buf32[1];
+ int rc;
+
+ buf16[0] = cpu_to_le16(cur->key.source_type);
+ buf16[1] = cpu_to_le16(cur->key.target_type);
+ buf16[2] = cpu_to_le16(cur->key.target_class);
+ buf16[3] = cpu_to_le16(cur->key.specified);
+ rc = put_entry(buf16, sizeof(u16), 4, fp);
+ if (rc)
+ return rc;
+ buf32[0] = cpu_to_le32(cur->datum.data);
+ rc = put_entry(buf32, sizeof(u32), 1, fp);
+ if (rc)
+ return rc;
+ return 0;
+}
+
+int avtab_write(struct policydb *p, struct avtab *a, void *fp)
+{
+ unsigned int i;
+ int rc = 0;
+ struct avtab_node *cur;
+ __le32 buf[1];
+
+ buf[0] = cpu_to_le32(a->nel);
+ rc = put_entry(buf, sizeof(u32), 1, fp);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < a->nslot; i++) {
+ for (cur = a->htable[i]; cur; cur = cur->next) {
+ rc = avtab_write_item(p, cur, fp);
+ if (rc)
+ return rc;
+ }
+ }
+
+ return rc;
+}
+void avtab_cache_init(void)
+{
+ avtab_node_cachep = kmem_cache_create("avtab_node",
+ sizeof(struct avtab_node),
+ 0, SLAB_PANIC, NULL);
+}
+
+void avtab_cache_destroy(void)
+{
+ kmem_cache_destroy(avtab_node_cachep);
+}