| /* |
| * Implementation of the access vector table type. |
| * |
| * Author : Stephen Smalley, <stephen.smalley.work@gmail.com> |
| */ |
| |
| /* 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/bitops.h> |
| #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 __ro_after_init; |
| static struct kmem_cache *avtab_xperms_cachep __ro_after_init; |
| |
| /* Based on MurmurHash3, written by Austin Appleby and placed in the |
| * public domain. |
| */ |
| static inline u32 avtab_hash(const struct avtab_key *keyp, u32 mask) |
| { |
| static const u32 c1 = 0xcc9e2d51; |
| static const u32 c2 = 0x1b873593; |
| static const u32 r1 = 15; |
| static const u32 r2 = 13; |
| static const u32 m = 5; |
| static const u32 n = 0xe6546b64; |
| |
| u32 hash = 0; |
| |
| #define mix(input) do { \ |
| u32 v = input; \ |
| v *= c1; \ |
| v = (v << r1) | (v >> (32 - r1)); \ |
| v *= c2; \ |
| hash ^= v; \ |
| hash = (hash << r2) | (hash >> (32 - r2)); \ |
| hash = hash * m + n; \ |
| } while (0) |
| |
| mix(keyp->target_class); |
| mix(keyp->target_type); |
| mix(keyp->source_type); |
| |
| #undef mix |
| |
| hash ^= hash >> 16; |
| hash *= 0x85ebca6b; |
| hash ^= hash >> 13; |
| hash *= 0xc2b2ae35; |
| hash ^= hash >> 16; |
| |
| return hash & mask; |
| } |
| |
| static struct avtab_node* |
| avtab_insert_node(struct avtab *h, struct avtab_node **dst, |
| const struct avtab_key *key, const struct avtab_datum *datum) |
| { |
| struct avtab_node *newnode; |
| struct avtab_extended_perms *xperms; |
| newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL); |
| if (newnode == NULL) |
| return NULL; |
| newnode->key = *key; |
| |
| if (key->specified & AVTAB_XPERMS) { |
| xperms = kmem_cache_zalloc(avtab_xperms_cachep, GFP_KERNEL); |
| if (xperms == NULL) { |
| kmem_cache_free(avtab_node_cachep, newnode); |
| return NULL; |
| } |
| *xperms = *(datum->u.xperms); |
| newnode->datum.u.xperms = xperms; |
| } else { |
| newnode->datum.u.data = datum->u.data; |
| } |
| |
| newnode->next = *dst; |
| *dst = newnode; |
| |
| h->nel++; |
| return newnode; |
| } |
| |
| static int avtab_insert(struct avtab *h, const struct avtab_key *key, |
| const struct avtab_datum *datum) |
| { |
| u32 hvalue; |
| struct avtab_node *prev, *cur, *newnode; |
| u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); |
| |
| if (!h || !h->nslot || h->nel == U32_MAX) |
| 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)) { |
| /* extended perms may not be unique */ |
| if (specified & AVTAB_XPERMS) |
| break; |
| 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, prev ? &prev->next : &h->htable[hvalue], |
| 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, |
| const struct avtab_key *key, |
| const struct avtab_datum *datum) |
| { |
| u32 hvalue; |
| struct avtab_node *prev, *cur; |
| u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); |
| |
| if (!h || !h->nslot || h->nel == U32_MAX) |
| 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, prev ? &prev->next : &h->htable[hvalue], |
| key, datum); |
| } |
| |
| /* 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, |
| const struct avtab_key *key) |
| { |
| u32 hvalue; |
| struct avtab_node *cur; |
| u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD); |
| |
| if (!h || !h->nslot) |
| 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, u16 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) |
| { |
| u32 i; |
| struct avtab_node *cur, *temp; |
| |
| if (!h) |
| return; |
| |
| for (i = 0; i < h->nslot; i++) { |
| cur = h->htable[i]; |
| while (cur) { |
| temp = cur; |
| cur = cur->next; |
| if (temp->key.specified & AVTAB_XPERMS) |
| kmem_cache_free(avtab_xperms_cachep, |
| temp->datum.u.xperms); |
| kmem_cache_free(avtab_node_cachep, temp); |
| } |
| } |
| kvfree(h->htable); |
| h->htable = NULL; |
| h->nel = 0; |
| h->nslot = 0; |
| h->mask = 0; |
| } |
| |
| void avtab_init(struct avtab *h) |
| { |
| h->htable = NULL; |
| h->nel = 0; |
| h->nslot = 0; |
| h->mask = 0; |
| } |
| |
| static int avtab_alloc_common(struct avtab *h, u32 nslot) |
| { |
| if (!nslot) |
| return 0; |
| |
| h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL); |
| if (!h->htable) |
| return -ENOMEM; |
| |
| h->nslot = nslot; |
| h->mask = nslot - 1; |
| return 0; |
| } |
| |
| int avtab_alloc(struct avtab *h, u32 nrules) |
| { |
| int rc; |
| u32 nslot = 0; |
| |
| if (nrules != 0) { |
| nslot = nrules > 3 ? rounddown_pow_of_two(nrules / 2) : 2; |
| if (nslot > MAX_AVTAB_HASH_BUCKETS) |
| nslot = MAX_AVTAB_HASH_BUCKETS; |
| |
| rc = avtab_alloc_common(h, nslot); |
| if (rc) |
| return rc; |
| } |
| |
| pr_debug("SELinux: %d avtab hash slots, %d rules.\n", nslot, nrules); |
| return 0; |
| } |
| |
| int avtab_alloc_dup(struct avtab *new, const struct avtab *orig) |
| { |
| return avtab_alloc_common(new, orig->nslot); |
| } |
| |
| #ifdef CONFIG_SECURITY_SELINUX_DEBUG |
| void avtab_hash_eval(struct avtab *h, const char *tag) |
| { |
| u32 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 += (unsigned long long)chain_len * chain_len; |
| } |
| } |
| |
| pr_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); |
| } |
| #endif /* CONFIG_SECURITY_SELINUX_DEBUG */ |
| |
| static const uint16_t spec_order[] = { |
| AVTAB_ALLOWED, |
| AVTAB_AUDITDENY, |
| AVTAB_AUDITALLOW, |
| AVTAB_TRANSITION, |
| AVTAB_CHANGE, |
| AVTAB_MEMBER, |
| AVTAB_XPERMS_ALLOWED, |
| AVTAB_XPERMS_AUDITALLOW, |
| AVTAB_XPERMS_DONTAUDIT |
| }; |
| |
| int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol, |
| int (*insertf)(struct avtab *a, const struct avtab_key *k, |
| const struct avtab_datum *d, void *p), |
| void *p) |
| { |
| __le16 buf16[4]; |
| u16 enabled; |
| u32 items, items2, val, i; |
| struct avtab_key key; |
| struct avtab_datum datum; |
| struct avtab_extended_perms xperms; |
| __le32 buf32[ARRAY_SIZE(xperms.perms.p)]; |
| int rc; |
| unsigned int set, vers = pol->policyvers; |
| |
| 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) { |
| pr_err("SELinux: avtab: truncated entry\n"); |
| return rc; |
| } |
| items2 = le32_to_cpu(buf32[0]); |
| if (items2 > ARRAY_SIZE(buf32)) { |
| pr_err("SELinux: avtab: entry overflow\n"); |
| return -EINVAL; |
| |
| } |
| rc = next_entry(buf32, fp, sizeof(u32)*items2); |
| if (rc) { |
| pr_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) { |
| pr_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) { |
| pr_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) { |
| pr_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))) { |
| pr_err("SELinux: avtab: null entry\n"); |
| return -EINVAL; |
| } |
| if ((val & AVTAB_AV) && |
| (val & AVTAB_TYPE)) { |
| pr_err("SELinux: avtab: entry has both access vectors and types\n"); |
| return -EINVAL; |
| } |
| if (val & AVTAB_XPERMS) { |
| pr_err("SELinux: avtab: entry has extended permissions\n"); |
| return -EINVAL; |
| } |
| |
| for (i = 0; i < ARRAY_SIZE(spec_order); i++) { |
| if (val & spec_order[i]) { |
| key.specified = spec_order[i] | enabled; |
| datum.u.data = le32_to_cpu(buf32[items++]); |
| rc = insertf(a, &key, &datum, p); |
| if (rc) |
| return rc; |
| } |
| } |
| |
| if (items != items2) { |
| pr_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) { |
| pr_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)) { |
| pr_err("SELinux: avtab: invalid type or class\n"); |
| return -EINVAL; |
| } |
| |
| set = hweight16(key.specified & (AVTAB_XPERMS | AVTAB_TYPE | AVTAB_AV)); |
| if (!set || set > 1) { |
| pr_err("SELinux: avtab: more than one specifier\n"); |
| return -EINVAL; |
| } |
| |
| if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) && |
| (key.specified & AVTAB_XPERMS)) { |
| pr_err("SELinux: avtab: policy version %u does not " |
| "support extended permissions rules and one " |
| "was specified\n", vers); |
| return -EINVAL; |
| } else if (key.specified & AVTAB_XPERMS) { |
| memset(&xperms, 0, sizeof(struct avtab_extended_perms)); |
| rc = next_entry(&xperms.specified, fp, sizeof(u8)); |
| if (rc) { |
| pr_err("SELinux: avtab: truncated entry\n"); |
| return rc; |
| } |
| rc = next_entry(&xperms.driver, fp, sizeof(u8)); |
| if (rc) { |
| pr_err("SELinux: avtab: truncated entry\n"); |
| return rc; |
| } |
| rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p)); |
| if (rc) { |
| pr_err("SELinux: avtab: truncated entry\n"); |
| return rc; |
| } |
| for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++) |
| xperms.perms.p[i] = le32_to_cpu(buf32[i]); |
| datum.u.xperms = &xperms; |
| } else { |
| rc = next_entry(buf32, fp, sizeof(u32)); |
| if (rc) { |
| pr_err("SELinux: avtab: truncated entry\n"); |
| return rc; |
| } |
| datum.u.data = le32_to_cpu(*buf32); |
| } |
| if ((key.specified & AVTAB_TYPE) && |
| !policydb_type_isvalid(pol, datum.u.data)) { |
| pr_err("SELinux: avtab: invalid type\n"); |
| return -EINVAL; |
| } |
| return insertf(a, &key, &datum, p); |
| } |
| |
| static int avtab_insertf(struct avtab *a, const struct avtab_key *k, |
| const 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) { |
| pr_err("SELinux: avtab: truncated table\n"); |
| goto bad; |
| } |
| nel = le32_to_cpu(buf[0]); |
| if (!nel) { |
| pr_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) |
| pr_err("SELinux: avtab: out of memory\n"); |
| else if (rc == -EEXIST) |
| pr_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, const struct avtab_node *cur, void *fp) |
| { |
| __le16 buf16[4]; |
| __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)]; |
| int rc; |
| unsigned int i; |
| |
| 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; |
| |
| if (cur->key.specified & AVTAB_XPERMS) { |
| rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp); |
| if (rc) |
| return rc; |
| rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp); |
| if (rc) |
| return rc; |
| for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++) |
| buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]); |
| rc = put_entry(buf32, sizeof(u32), |
| ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp); |
| } else { |
| buf32[0] = cpu_to_le32(cur->datum.u.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) |
| { |
| u32 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 __init avtab_cache_init(void) |
| { |
| avtab_node_cachep = kmem_cache_create("avtab_node", |
| sizeof(struct avtab_node), |
| 0, SLAB_PANIC, NULL); |
| avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms", |
| sizeof(struct avtab_extended_perms), |
| 0, SLAB_PANIC, NULL); |
| } |