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 const char *p, *keyp;
51 size_t size;
52 unsigned int val;
53
54 val = 0;
55 keyp = (const char*)key;
56 size = strlen(keyp);
57 for (p = keyp; ((size_t) (p - keyp)) < size; p++)
58 val =
59 (val << 4 | (val >> (8 * sizeof(unsigned int) - 4))) ^ (*p);
60 return val & (h->size - 1);
61 }
62
cil_strpool_compare(hashtab_t h,const_hashtab_key_t key1,const_hashtab_key_t key2)63 static int cil_strpool_compare(hashtab_t h __attribute__ ((unused)), const_hashtab_key_t key1, const_hashtab_key_t key2)
64 {
65 const char *keyp1 = (const char*)key1;
66 const char *keyp2 = (const char*)key2;
67 return strcmp(keyp1, keyp2);
68 }
69
cil_strpool_add(const char * str)70 char *cil_strpool_add(const char *str)
71 {
72 struct cil_strpool_entry *strpool_ref = NULL;
73
74 pthread_mutex_lock(&cil_strpool_mutex);
75
76 strpool_ref = hashtab_search(cil_strpool_tab, (hashtab_key_t)str);
77 if (strpool_ref == NULL) {
78 strpool_ref = cil_malloc(sizeof(*strpool_ref));
79 strpool_ref->str = cil_strdup(str);
80 int rc = hashtab_insert(cil_strpool_tab, (hashtab_key_t)strpool_ref->str, strpool_ref);
81 if (rc != SEPOL_OK) {
82 pthread_mutex_unlock(&cil_strpool_mutex);
83 (*cil_mem_error_handler)();
84 pthread_mutex_lock(&cil_strpool_mutex);
85 }
86 }
87
88 pthread_mutex_unlock(&cil_strpool_mutex);
89 return strpool_ref->str;
90 }
91
cil_strpool_entry_destroy(hashtab_key_t k,hashtab_datum_t d,void * args)92 static int cil_strpool_entry_destroy(hashtab_key_t k __attribute__ ((unused)), hashtab_datum_t d, void *args __attribute__ ((unused)))
93 {
94 struct cil_strpool_entry *strpool_ref = (struct cil_strpool_entry*)d;
95 free(strpool_ref->str);
96 free(strpool_ref);
97 return SEPOL_OK;
98 }
99
cil_strpool_init(void)100 void cil_strpool_init(void)
101 {
102 pthread_mutex_lock(&cil_strpool_mutex);
103 if (cil_strpool_tab == NULL) {
104 cil_strpool_tab = hashtab_create(cil_strpool_hash, cil_strpool_compare, CIL_STRPOOL_TABLE_SIZE);
105 if (cil_strpool_tab == NULL) {
106 pthread_mutex_unlock(&cil_strpool_mutex);
107 (*cil_mem_error_handler)();
108 return;
109 }
110 }
111 cil_strpool_readers++;
112 pthread_mutex_unlock(&cil_strpool_mutex);
113 }
114
cil_strpool_destroy(void)115 void cil_strpool_destroy(void)
116 {
117 pthread_mutex_lock(&cil_strpool_mutex);
118 cil_strpool_readers--;
119 if (cil_strpool_readers == 0) {
120 hashtab_map(cil_strpool_tab, cil_strpool_entry_destroy, NULL);
121 hashtab_destroy(cil_strpool_tab);
122 cil_strpool_tab = NULL;
123 }
124 pthread_mutex_unlock(&cil_strpool_mutex);
125 }
126