In four separate functions within avtab, the same comparison logic is
used. The only difference is how the result is handled or whether there
is a unique specifier value to be checked for or used.
Extracting this functionality into the avtab_node_cmp() function unifies
the comparison logic between searching and insertion and gets rid of
duplicative code so that the implementation is easier to maintain.
Signed-off-by: Jacob Satterfield <jsatterfield.linux@xxxxxxxxx>
Reviewed-by: Stephen Smalley <stephen.smalley.work@xxxxxxxxx>
---
security/selinux/ss/avtab.c | 101 +++++++++++++++---------------------
1 file changed, 41 insertions(+), 60 deletions(-)
diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
index 8751a602ead2..697eb4352439 100644
--- a/security/selinux/ss/avtab.c
+++ b/security/selinux/ss/avtab.c
@@ -96,12 +96,34 @@ avtab_insert_node(struct avtab *h, struct avtab_node **dst,
return newnode;
}
+static int avtab_node_cmp(const struct avtab_key *key1,
+ const struct avtab_key *key2)
+{
+ u16 specified = key1->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
+
+ if (key1->source_type == key2->source_type &&
+ key1->target_type == key2->target_type &&
+ key1->target_class == key2->target_class &&
+ (specified & key2->specified))
+ return 0;
+ if (key1->source_type < key2->source_type)
+ return -1;
+ if (key1->source_type == key2->source_type &&
+ key1->target_type < key2->target_type)
+ return -1;
+ if (key1->source_type == key2->source_type &&
+ key1->target_type == key2->target_type &&
+ key1->target_class < key2->target_class)
+ return -1;
+ return 1;
+}
+
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);
+ int cmp;
if (!h || !h->nslot || h->nel == U32_MAX)
return -EINVAL;
@@ -110,23 +132,11 @@ static int avtab_insert(struct avtab *h, const struct avtab_key *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)) {
- /* extended perms may not be unique */
- if (specified & AVTAB_XPERMS)
- break;
+ cmp = avtab_node_cmp(key, &cur->key);
+ /* extended perms may not be unique */
+ if (cmp == 0 && !(key->specified & AVTAB_XPERMS))
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)
+ if (cmp <= 0)
break;
}
@@ -148,7 +158,7 @@ struct avtab_node *avtab_insert_nonunique(struct avtab *h,
{
u32 hvalue;
struct avtab_node *prev, *cur;
- u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
+ int cmp;
if (!h || !h->nslot || h->nel == U32_MAX)
return NULL;
@@ -156,19 +166,8 @@ struct avtab_node *avtab_insert_nonunique(struct avtab *h,
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)
+ cmp = avtab_node_cmp(key, &cur->key);
+ if (cmp <= 0)
break;
}
return avtab_insert_node(h, prev ? &prev->next : &h->htable[hvalue],
@@ -183,7 +182,7 @@ struct avtab_node *avtab_search_node(struct avtab *h,
{
u32 hvalue;
struct avtab_node *cur;
- u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
+ int cmp;
if (!h || !h->nslot)
return NULL;
@@ -191,20 +190,10 @@ struct avtab_node *avtab_search_node(struct avtab *h,
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))
+ cmp = avtab_node_cmp(key, &cur->key);
+ if (cmp == 0)
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)
+ if (cmp < 0)
break;
}
return NULL;
@@ -213,27 +202,19 @@ struct avtab_node *avtab_search_node(struct avtab *h,
struct avtab_node*
avtab_search_node_next(struct avtab_node *node, u16 specified)
{
+ struct avtab_key tmp_key;
struct avtab_node *cur;
+ int cmp;
if (!node)
return NULL;
-
- specified &= ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
+ tmp_key = node->key;
+ tmp_key.specified = specified;
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))
+ cmp = avtab_node_cmp(&tmp_key, &cur->key);
+ if (cmp == 0)
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)
+ if (cmp < 0)
break;
}
return NULL;
--
2.41.0
