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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /security/selinux/ss/hashtab.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'security/selinux/ss/hashtab.c')
-rw-r--r--security/selinux/ss/hashtab.c167
1 files changed, 167 insertions, 0 deletions
diff --git a/security/selinux/ss/hashtab.c b/security/selinux/ss/hashtab.c
new file mode 100644
index 000000000000..26661fcc00ce
--- /dev/null
+++ b/security/selinux/ss/hashtab.c
@@ -0,0 +1,167 @@
1/*
2 * Implementation of the hash table type.
3 *
4 * Author : Stephen Smalley, <sds@epoch.ncsc.mil>
5 */
6#include <linux/kernel.h>
7#include <linux/slab.h>
8#include <linux/errno.h>
9#include "hashtab.h"
10
11struct hashtab *hashtab_create(u32 (*hash_value)(struct hashtab *h, void *key),
12 int (*keycmp)(struct hashtab *h, void *key1, void *key2),
13 u32 size)
14{
15 struct hashtab *p;
16 u32 i;
17
18 p = kmalloc(sizeof(*p), GFP_KERNEL);
19 if (p == NULL)
20 return p;
21
22 memset(p, 0, sizeof(*p));
23 p->size = size;
24 p->nel = 0;
25 p->hash_value = hash_value;
26 p->keycmp = keycmp;
27 p->htable = kmalloc(sizeof(*(p->htable)) * size, GFP_KERNEL);
28 if (p->htable == NULL) {
29 kfree(p);
30 return NULL;
31 }
32
33 for (i = 0; i < size; i++)
34 p->htable[i] = NULL;
35
36 return p;
37}
38
39int hashtab_insert(struct hashtab *h, void *key, void *datum)
40{
41 u32 hvalue;
42 struct hashtab_node *prev, *cur, *newnode;
43
44 if (!h || h->nel == HASHTAB_MAX_NODES)
45 return -EINVAL;
46
47 hvalue = h->hash_value(h, key);
48 prev = NULL;
49 cur = h->htable[hvalue];
50 while (cur && h->keycmp(h, key, cur->key) > 0) {
51 prev = cur;
52 cur = cur->next;
53 }
54
55 if (cur && (h->keycmp(h, key, cur->key) == 0))
56 return -EEXIST;
57
58 newnode = kmalloc(sizeof(*newnode), GFP_KERNEL);
59 if (newnode == NULL)
60 return -ENOMEM;
61 memset(newnode, 0, sizeof(*newnode));
62 newnode->key = key;
63 newnode->datum = datum;
64 if (prev) {
65 newnode->next = prev->next;
66 prev->next = newnode;
67 } else {
68 newnode->next = h->htable[hvalue];
69 h->htable[hvalue] = newnode;
70 }
71
72 h->nel++;
73 return 0;
74}
75
76void *hashtab_search(struct hashtab *h, void *key)
77{
78 u32 hvalue;
79 struct hashtab_node *cur;
80
81 if (!h)
82 return NULL;
83
84 hvalue = h->hash_value(h, key);
85 cur = h->htable[hvalue];
86 while (cur != NULL && h->keycmp(h, key, cur->key) > 0)
87 cur = cur->next;
88
89 if (cur == NULL || (h->keycmp(h, key, cur->key) != 0))
90 return NULL;
91
92 return cur->datum;
93}
94
95void hashtab_destroy(struct hashtab *h)
96{
97 u32 i;
98 struct hashtab_node *cur, *temp;
99
100 if (!h)
101 return;
102
103 for (i = 0; i < h->size; i++) {
104 cur = h->htable[i];
105 while (cur != NULL) {
106 temp = cur;
107 cur = cur->next;
108 kfree(temp);
109 }
110 h->htable[i] = NULL;
111 }
112
113 kfree(h->htable);
114 h->htable = NULL;
115
116 kfree(h);
117}
118
119int hashtab_map(struct hashtab *h,
120 int (*apply)(void *k, void *d, void *args),
121 void *args)
122{
123 u32 i;
124 int ret;
125 struct hashtab_node *cur;
126
127 if (!h)
128 return 0;
129
130 for (i = 0; i < h->size; i++) {
131 cur = h->htable[i];
132 while (cur != NULL) {
133 ret = apply(cur->key, cur->datum, args);
134 if (ret)
135 return ret;
136 cur = cur->next;
137 }
138 }
139 return 0;
140}
141
142
143void hashtab_stat(struct hashtab *h, struct hashtab_info *info)
144{
145 u32 i, chain_len, slots_used, max_chain_len;
146 struct hashtab_node *cur;
147
148 slots_used = 0;
149 max_chain_len = 0;
150 for (slots_used = max_chain_len = i = 0; i < h->size; i++) {
151 cur = h->htable[i];
152 if (cur) {
153 slots_used++;
154 chain_len = 0;
155 while (cur) {
156 chain_len++;
157 cur = cur->next;
158 }
159
160 if (chain_len > max_chain_len)
161 max_chain_len = chain_len;
162 }
163 }
164
165 info->slots_used = slots_used;
166 info->max_chain_len = max_chain_len;
167}