1 /*
2 * Copyright 2014 Tresys Technology, LLC. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * 1. Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 *
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY TRESYS TECHNOLOGY, LLC ``AS IS'' AND ANY EXPRESS
15 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
16 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
17 * EVENT SHALL TRESYS TECHNOLOGY, LLC OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
18 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
21 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
22 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
23 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * The views and conclusions contained in the software and documentation are those
26 * of the authors and should not be interpreted as representing official policies,
27 * either expressed or implied, of Tresys Technology, LLC.
28 */
29
30 #include <pthread.h>
31 #include <stdlib.h>
32 #include <stdio.h>
33 #include <string.h>
34 #include "cil_mem.h"
35 #include "cil_strpool.h"
36
37 #include "cil_log.h"
38 #define CIL_STRPOOL_TABLE_SIZE 1 << 15
39
40 struct cil_strpool_entry {
41 char *str;
42 };
43
44 static pthread_mutex_t cil_strpool_mutex = PTHREAD_MUTEX_INITIALIZER;
45 static unsigned int cil_strpool_readers = 0;
46 static hashtab_t cil_strpool_tab = NULL;
47
cil_strpool_hash(hashtab_t h,const_hashtab_key_t key)48 static unsigned int cil_strpool_hash(hashtab_t h, const_hashtab_key_t key)
49 {
50 unsigned int hash = 5381;
51 unsigned char c;
52
53 while ((c = *(unsigned const char *)key++))
54 hash = ((hash << 5) + hash) ^ c;
55
56 return hash & (h->size - 1);
57 }
58
cil_strpool_compare(hashtab_t h,const_hashtab_key_t key1,const_hashtab_key_t key2)59 static int cil_strpool_compare(hashtab_t h __attribute__ ((unused)), const_hashtab_key_t key1, const_hashtab_key_t key2)
60 {
61 return strcmp(key1, key2);
62 }
63
cil_strpool_add(const char * str)64 char *cil_strpool_add(const char *str)
65 {
66 struct cil_strpool_entry *strpool_ref = NULL;
67
68 pthread_mutex_lock(&cil_strpool_mutex);
69
70 strpool_ref = hashtab_search(cil_strpool_tab, str);
71 if (strpool_ref == NULL) {
72 int rc;
73 strpool_ref = cil_malloc(sizeof(*strpool_ref));
74 strpool_ref->str = cil_strdup(str);
75 rc = hashtab_insert(cil_strpool_tab, strpool_ref->str, strpool_ref);
76 if (rc != SEPOL_OK) {
77 pthread_mutex_unlock(&cil_strpool_mutex);
78 cil_log(CIL_ERR, "Failed to allocate memory\n");
79 exit(1);
80 }
81 }
82
83 pthread_mutex_unlock(&cil_strpool_mutex);
84 return strpool_ref->str;
85 }
86
cil_strpool_entry_destroy(hashtab_key_t k,hashtab_datum_t d,void * args)87 static int cil_strpool_entry_destroy(hashtab_key_t k __attribute__ ((unused)), hashtab_datum_t d, void *args __attribute__ ((unused)))
88 {
89 struct cil_strpool_entry *strpool_ref = (struct cil_strpool_entry*)d;
90 free(strpool_ref->str);
91 free(strpool_ref);
92 return SEPOL_OK;
93 }
94
cil_strpool_init(void)95 void cil_strpool_init(void)
96 {
97 pthread_mutex_lock(&cil_strpool_mutex);
98 if (cil_strpool_tab == NULL) {
99 cil_strpool_tab = hashtab_create(cil_strpool_hash, cil_strpool_compare, CIL_STRPOOL_TABLE_SIZE);
100 if (cil_strpool_tab == NULL) {
101 pthread_mutex_unlock(&cil_strpool_mutex);
102 cil_log(CIL_ERR, "Failed to allocate memory\n");
103 exit(1);
104 }
105 }
106 cil_strpool_readers++;
107 pthread_mutex_unlock(&cil_strpool_mutex);
108 }
109
cil_strpool_destroy(void)110 void cil_strpool_destroy(void)
111 {
112 pthread_mutex_lock(&cil_strpool_mutex);
113 cil_strpool_readers--;
114 if (cil_strpool_readers == 0) {
115 hashtab_map(cil_strpool_tab, cil_strpool_entry_destroy, NULL);
116 hashtab_destroy(cil_strpool_tab);
117 cil_strpool_tab = NULL;
118 }
119 pthread_mutex_unlock(&cil_strpool_mutex);
120 }
121