1 files changed, 178 insertions, 0 deletions
diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c
new file mode 100644
index 000000000..ebfdaa31e
--- /dev/null
+++ b/security/selinux/ss/hashtab.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implementation of the hash table type.
+ *
+ * Author : Stephen Smalley, <sds@tycho.nsa.gov>
+ */
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include "hashtab.h"
+
+static struct kmem_cache *hashtab_node_cachep;
+
+struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, const void *key),
+			       int (*keycmp)(struct hashtab *h, const void *key1, const void *key2),
+			       u32 size)
+{
+	struct hashtab *p;
+	u32 i;
+
+	p = kzalloc(sizeof(*p), GFP_KERNEL);
+	if (!p)
+		return p;
+
+	p->size = size;
+	p->nel = 0;
+	p->hash_value = hash_value;
+	p->keycmp = keycmp;
+	p->htable = kmalloc_array(size, sizeof(*p->htable), GFP_KERNEL);
+	if (!p->htable) {
+		kfree(p);
+		return NULL;
+	}
+
+	for (i = 0; i < size; i++)
+		p->htable[i] = NULL;
+
+	return p;
+}
+
+int hashtab_insert(struct hashtab *h, void *key, void *datum)
+{
+	u32 hvalue;
+	struct hashtab_node *prev, *cur, *newnode;
+
+	cond_resched();
+
+	if (!h || h->nel == HASHTAB_MAX_NODES)
+		return -EINVAL;
+
+	hvalue = h->hash_value(h, key);
+	prev = NULL;
+	cur = h->htable[hvalue];
+	while (cur && h->keycmp(h, key, cur->key) > 0) {
+		prev = cur;
+		cur = cur->next;
+	}
+
+	if (cur && (h->keycmp(h, key, cur->key) == 0))
+		return -EEXIST;
+
+	newnode = kmem_cache_zalloc(hashtab_node_cachep, GFP_KERNEL);
+	if (!newnode)
+		return -ENOMEM;
+	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 0;
+}
+
+void *hashtab_search(struct hashtab *h, const void *key)
+{
+	u32 hvalue;
+	struct hashtab_node *cur;
+
+	if (!h)
+		return NULL;
+
+	hvalue = h->hash_value(h, key);
+	cur = h->htable[hvalue];
+	while (cur && h->keycmp(h, key, cur->key) > 0)
+		cur = cur->next;
+
+	if (!cur || (h->keycmp(h, key, cur->key) != 0))
+		return NULL;
+
+	return cur->datum;
+}
+
+void hashtab_destroy(struct hashtab *h)
+{
+	u32 i;
+	struct hashtab_node *cur, *temp;
+
+	if (!h)
+		return;
+
+	for (i = 0; i < h->size; i++) {
+		cur = h->htable[i];
+		while (cur) {
+			temp = cur;
+			cur = cur->next;
+			kmem_cache_free(hashtab_node_cachep, temp);
+		}
+		h->htable[i] = NULL;
+	}
+
+	kfree(h->htable);
+	h->htable = NULL;
+
+	kfree(h);
+}
+
+int hashtab_map(struct hashtab *h,
+		int (*apply)(void *k, void *d, void *args),
+		void *args)
+{
+	u32 i;
+	int ret;
+	struct hashtab_node *cur;
+
+	if (!h)
+		return 0;
+
+	for (i = 0; i < h->size; i++) {
+		cur = h->htable[i];
+		while (cur) {
+			ret = apply(cur->key, cur->datum, args);
+			if (ret)
+				return ret;
+			cur = cur->next;
+		}
+	}
+	return 0;
+}
+
+
+void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
+{
+	u32 i, chain_len, slots_used, max_chain_len;
+	struct hashtab_node *cur;
+
+	slots_used = 0;
+	max_chain_len = 0;
+	for (i = 0; i < h->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;
+		}
+	}
+
+	info->slots_used = slots_used;
+	info->max_chain_len = max_chain_len;
+}
+
+void __init hashtab_cache_init(void)
+{
+		hashtab_node_cachep = kmem_cache_create("hashtab_node",
+			sizeof(struct hashtab_node),
+			0, SLAB_PANIC, NULL);
+}