Line data Source code
1 : /*
2 : * Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
3 : * (Royal Institute of Technology, Stockholm, Sweden).
4 : * All rights reserved.
5 : *
6 : * Redistribution and use in source and binary forms, with or without
7 : * modification, are permitted provided that the following conditions
8 : * are met:
9 : *
10 : * 1. Redistributions of source code must retain the above copyright
11 : * notice, this list of conditions and the following disclaimer.
12 : *
13 : * 2. Redistributions in binary form must reproduce the above copyright
14 : * notice, this list of conditions and the following disclaimer in the
15 : * documentation and/or other materials provided with the distribution.
16 : *
17 : * 3. Neither the name of the Institute nor the names of its contributors
18 : * may be used to endorse or promote products derived from this software
19 : * without specific prior written permission.
20 : *
21 : * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 : * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 : * SUCH DAMAGE.
32 : */
33 :
34 : #include "krb5_locl.h"
35 : #include "store-int.h"
36 : #include <assert.h>
37 :
38 : typedef struct emem_storage{
39 : unsigned char *base;
40 : size_t size;
41 : size_t len;
42 : unsigned char *ptr;
43 : }emem_storage;
44 :
45 : static ssize_t
46 327974 : emem_fetch(krb5_storage *sp, void *data, size_t size)
47 : {
48 327974 : emem_storage *s = (emem_storage*)sp->data;
49 :
50 327974 : assert(data != NULL && s->ptr != NULL);
51 :
52 327974 : if((size_t)(s->base + s->len - s->ptr) < size)
53 0 : size = s->base + s->len - s->ptr;
54 327974 : memmove(data, s->ptr, size);
55 327974 : sp->seek(sp, size, SEEK_CUR);
56 327974 : return size;
57 : }
58 :
59 : static ssize_t
60 3002545 : emem_store(krb5_storage *sp, const void *data, size_t size)
61 : {
62 : emem_storage *s;
63 :
64 3002545 : if (size == 0) {
65 72874 : sp->seek(sp, 0, SEEK_CUR);
66 72874 : return 0;
67 : }
68 :
69 2929671 : s = (emem_storage*)sp->data;
70 :
71 2929671 : assert(data != NULL);
72 :
73 2929671 : if(size > (size_t)(s->base + s->size - s->ptr)){
74 : void *base;
75 : size_t sz, off;
76 29375 : off = s->ptr - s->base;
77 29375 : sz = off + size;
78 29375 : if (sz < 4096)
79 29367 : sz *= 2;
80 29375 : base = realloc(s->base, sz);
81 29375 : if(base == NULL)
82 0 : return -1;
83 29375 : s->size = sz;
84 29375 : s->base = base;
85 29375 : s->ptr = (unsigned char*)base + off;
86 : }
87 2929671 : memmove(s->ptr, data, size);
88 2929671 : sp->seek(sp, size, SEEK_CUR);
89 2929671 : return size;
90 : }
91 :
92 : static off_t
93 8628886 : emem_seek(krb5_storage *sp, off_t offset, int whence)
94 : {
95 8628886 : emem_storage *s = (emem_storage*)sp->data;
96 8628886 : switch(whence){
97 4642417 : case SEEK_SET:
98 4642417 : if((size_t)offset > s->size)
99 0 : offset = s->size;
100 4642417 : if(offset < 0)
101 0 : offset = 0;
102 4642417 : s->ptr = s->base + offset;
103 4642417 : if((size_t)offset > s->len)
104 2929671 : s->len = offset;
105 4642417 : break;
106 3658493 : case SEEK_CUR:
107 3658493 : sp->seek(sp,s->ptr - s->base + offset, SEEK_SET);
108 3658493 : break;
109 327976 : case SEEK_END:
110 327976 : sp->seek(sp, s->len + offset, SEEK_SET);
111 327976 : break;
112 0 : default:
113 0 : errno = EINVAL;
114 0 : return -1;
115 : }
116 8628886 : return s->ptr - s->base;
117 : }
118 :
119 : static int
120 0 : emem_trunc(krb5_storage *sp, off_t offset)
121 : {
122 0 : emem_storage *s = (emem_storage*)sp->data;
123 : /*
124 : * If offset is larget then current size, or current size is
125 : * shrunk more then half of the current size, adjust buffer.
126 : */
127 0 : if (offset == 0) {
128 0 : free(s->base);
129 0 : s->size = 0;
130 0 : s->base = NULL;
131 0 : s->ptr = NULL;
132 0 : } else if ((size_t)offset > s->size || (s->size / 2) > (size_t)offset) {
133 : void *base;
134 : size_t off;
135 0 : off = s->ptr - s->base;
136 0 : base = realloc(s->base, offset);
137 0 : if(base == NULL)
138 0 : return ENOMEM;
139 0 : if ((size_t)offset > s->size)
140 0 : memset((char *)base + s->size, 0, offset - s->size);
141 0 : s->size = offset;
142 0 : s->base = base;
143 0 : s->ptr = (unsigned char *)base + off;
144 : }
145 0 : s->len = offset;
146 0 : if ((s->ptr - s->base) > offset)
147 0 : s->ptr = s->base + offset;
148 0 : return 0;
149 : }
150 :
151 :
152 : static void
153 327974 : emem_free(krb5_storage *sp)
154 : {
155 327974 : emem_storage *s = sp->data;
156 :
157 327974 : assert(s->base != NULL);
158 :
159 327974 : memset_s(s->base, s->len, 0, s->len);
160 327974 : free(s->base);
161 327974 : }
162 :
163 : /**
164 : * Create a elastic (allocating) memory storage backend. Memory is
165 : * allocated on demand. Free returned krb5_storage with
166 : * krb5_storage_free().
167 : *
168 : * @return A krb5_storage on success, or NULL on out of memory error.
169 : *
170 : * @ingroup krb5_storage
171 : *
172 : * @sa krb5_storage_from_mem()
173 : * @sa krb5_storage_from_readonly_mem()
174 : * @sa krb5_storage_from_fd()
175 : * @sa krb5_storage_from_data()
176 : * @sa krb5_storage_from_socket()
177 : */
178 :
179 : KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
180 327974 : krb5_storage_emem(void)
181 : {
182 : krb5_storage *sp;
183 : emem_storage *s;
184 :
185 327974 : sp = malloc(sizeof(krb5_storage));
186 327974 : if (sp == NULL)
187 0 : return NULL;
188 :
189 327974 : s = malloc(sizeof(*s));
190 327974 : if (s == NULL) {
191 0 : free(sp);
192 0 : return NULL;
193 : }
194 327974 : sp->data = s;
195 327974 : sp->flags = 0;
196 327974 : sp->eof_code = HEIM_ERR_EOF;
197 327974 : s->size = 1024;
198 327974 : s->base = calloc(1, s->size);
199 327974 : if (s->base == NULL) {
200 0 : free(sp);
201 0 : free(s);
202 0 : return NULL;
203 : }
204 327974 : s->len = 0;
205 327974 : s->ptr = s->base;
206 327974 : sp->fetch = emem_fetch;
207 327974 : sp->store = emem_store;
208 327974 : sp->seek = emem_seek;
209 327974 : sp->trunc = emem_trunc;
210 327974 : sp->fsync = NULL;
211 327974 : sp->free = emem_free;
212 327974 : sp->max_alloc = UINT_MAX/8;
213 327974 : return sp;
214 : }
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