| /* |
| * 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. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/vmalloc.h> |
| #include <linux/errno.h> |
| |
| #include "avtab.h" |
| #include "policydb.h" |
| |
| #define AVTAB_HASH(keyp) \ |
| ((keyp->target_class + \ |
| (keyp->target_type << 2) + \ |
| (keyp->source_type << 9)) & \ |
| AVTAB_HASH_MASK) |
| |
| static kmem_cache_t *avtab_node_cachep; |
| |
| 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_alloc(avtab_node_cachep, GFP_KERNEL); |
| if (newnode == NULL) |
| return NULL; |
| memset(newnode, 0, sizeof(struct avtab_node)); |
| 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) |
| return -EINVAL; |
| |
| hvalue = AVTAB_HASH(key); |
| 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, *newnode; |
| u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); |
| |
| if (!h) |
| return NULL; |
| hvalue = AVTAB_HASH(key); |
| 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, cur, key, datum); |
| |
| return newnode; |
| } |
| |
| 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) |
| return NULL; |
| |
| hvalue = AVTAB_HASH(key); |
| 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) |
| return NULL; |
| |
| hvalue = AVTAB_HASH(key); |
| 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 < AVTAB_SIZE; i++) { |
| cur = h->htable[i]; |
| while (cur != NULL) { |
| temp = cur; |
| cur = cur->next; |
| kmem_cache_free(avtab_node_cachep, temp); |
| } |
| h->htable[i] = NULL; |
| } |
| vfree(h->htable); |
| h->htable = NULL; |
| } |
| |
| |
| int avtab_init(struct avtab *h) |
| { |
| int i; |
| |
| h->htable = vmalloc(sizeof(*(h->htable)) * AVTAB_SIZE); |
| if (!h->htable) |
| return -ENOMEM; |
| for (i = 0; i < AVTAB_SIZE; i++) |
| h->htable[i] = NULL; |
| h->nel = 0; |
| return 0; |
| } |
| |
| void avtab_hash_eval(struct avtab *h, char *tag) |
| { |
| int i, chain_len, slots_used, max_chain_len; |
| struct avtab_node *cur; |
| |
| slots_used = 0; |
| max_chain_len = 0; |
| for (i = 0; i < AVTAB_SIZE; 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; |
| } |
| } |
| |
| printk(KERN_INFO "%s: %d entries and %d/%d buckets used, longest " |
| "chain length %d\n", tag, h->nel, slots_used, AVTAB_SIZE, |
| max_chain_len); |
| } |
| |
| static uint16_t spec_order[] = { |
| AVTAB_ALLOWED, |
| AVTAB_AUDITDENY, |
| AVTAB_AUDITALLOW, |
| AVTAB_TRANSITION, |
| AVTAB_CHANGE, |
| AVTAB_MEMBER |
| }; |
| |
| int avtab_read_item(void *fp, u32 vers, struct avtab *a, |
| 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; |
| struct avtab_key key; |
| struct avtab_datum datum; |
| int i, rc; |
| |
| 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 < 0) { |
| printk(KERN_ERR "security: avtab: truncated entry\n"); |
| return -1; |
| } |
| items2 = le32_to_cpu(buf32[0]); |
| if (items2 > ARRAY_SIZE(buf32)) { |
| printk(KERN_ERR "security: avtab: entry overflow\n"); |
| return -1; |
| |
| } |
| rc = next_entry(buf32, fp, sizeof(u32)*items2); |
| if (rc < 0) { |
| printk(KERN_ERR "security: avtab: truncated entry\n"); |
| return -1; |
| } |
| items = 0; |
| |
| val = le32_to_cpu(buf32[items++]); |
| key.source_type = (u16)val; |
| if (key.source_type != val) { |
| printk("security: avtab: truncated source type\n"); |
| return -1; |
| } |
| val = le32_to_cpu(buf32[items++]); |
| key.target_type = (u16)val; |
| if (key.target_type != val) { |
| printk("security: avtab: truncated target type\n"); |
| return -1; |
| } |
| val = le32_to_cpu(buf32[items++]); |
| key.target_class = (u16)val; |
| if (key.target_class != val) { |
| printk("security: avtab: truncated target class\n"); |
| return -1; |
| } |
| |
| val = le32_to_cpu(buf32[items++]); |
| enabled = (val & AVTAB_ENABLED_OLD) ? AVTAB_ENABLED : 0; |
| |
| if (!(val & (AVTAB_AV | AVTAB_TYPE))) { |
| printk("security: avtab: null entry\n"); |
| return -1; |
| } |
| if ((val & AVTAB_AV) && |
| (val & AVTAB_TYPE)) { |
| printk("security: avtab: entry has both access vectors and types\n"); |
| 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) { |
| printk("security: avtab: entry only had %d items, expected %d\n", items2, items); |
| return -1; |
| } |
| return 0; |
| } |
| |
| rc = next_entry(buf16, fp, sizeof(u16)*4); |
| if (rc < 0) { |
| printk("security: avtab: truncated entry\n"); |
| 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++]); |
| |
| rc = next_entry(buf32, fp, sizeof(u32)); |
| if (rc < 0) { |
| printk("security: avtab: truncated entry\n"); |
| return -1; |
| } |
| datum.data = le32_to_cpu(*buf32); |
| 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, u32 vers) |
| { |
| int rc; |
| __le32 buf[1]; |
| u32 nel, i; |
| |
| |
| rc = next_entry(buf, fp, sizeof(u32)); |
| if (rc < 0) { |
| printk(KERN_ERR "security: avtab: truncated table\n"); |
| goto bad; |
| } |
| nel = le32_to_cpu(buf[0]); |
| if (!nel) { |
| printk(KERN_ERR "security: avtab: table is empty\n"); |
| rc = -EINVAL; |
| goto bad; |
| } |
| for (i = 0; i < nel; i++) { |
| rc = avtab_read_item(fp,vers, a, avtab_insertf, NULL); |
| if (rc) { |
| if (rc == -ENOMEM) |
| printk(KERN_ERR "security: avtab: out of memory\n"); |
| else if (rc == -EEXIST) |
| printk(KERN_ERR "security: avtab: duplicate entry\n"); |
| else |
| rc = -EINVAL; |
| goto bad; |
| } |
| } |
| |
| rc = 0; |
| out: |
| return rc; |
| |
| bad: |
| avtab_destroy(a); |
| goto out; |
| } |
| |
| void avtab_cache_init(void) |
| { |
| avtab_node_cachep = kmem_cache_create("avtab_node", |
| sizeof(struct avtab_node), |
| 0, SLAB_PANIC, NULL, NULL); |
| } |
| |
| void avtab_cache_destroy(void) |
| { |
| kmem_cache_destroy (avtab_node_cachep); |
| } |