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[heimdal.git] / lib / krb5 / store_mem.c
blobb79bc19155ad23070e8d456eab2fbfc048391bb4
1 /*
2 * Copyright (c) 1997 - 2000, 2002 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
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.
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.
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.
34 #include "krb5_locl.h"
35 #include "store-int.h"
37 typedef struct mem_storage{
38 unsigned char *base;
39 size_t size;
40 unsigned char *ptr;
41 }mem_storage;
43 static ssize_t
44 mem_fetch(krb5_storage *sp, void *data, size_t size)
46 mem_storage *s = (mem_storage*)sp->data;
47 if(size > s->base + s->size - s->ptr)
48 size = s->base + s->size - s->ptr;
49 memmove(data, s->ptr, size);
50 sp->seek(sp, size, SEEK_CUR);
51 return size;
54 static ssize_t
55 mem_store(krb5_storage *sp, const void *data, size_t size)
57 mem_storage *s = (mem_storage*)sp->data;
58 if(size > s->base + s->size - s->ptr)
59 size = s->base + s->size - s->ptr;
60 memmove(s->ptr, data, size);
61 sp->seek(sp, size, SEEK_CUR);
62 return size;
65 static ssize_t
66 mem_no_store(krb5_storage *sp, const void *data, size_t size)
68 return -1;
71 static off_t
72 mem_seek(krb5_storage *sp, off_t offset, int whence)
74 mem_storage *s = (mem_storage*)sp->data;
75 switch(whence){
76 case SEEK_SET:
77 if(offset > s->size)
78 offset = s->size;
79 if(offset < 0)
80 offset = 0;
81 s->ptr = s->base + offset;
82 break;
83 case SEEK_CUR:
84 return sp->seek(sp, s->ptr - s->base + offset, SEEK_SET);
85 case SEEK_END:
86 return sp->seek(sp, s->size + offset, SEEK_SET);
87 default:
88 errno = EINVAL;
89 return -1;
91 return s->ptr - s->base;
94 static int
95 mem_trunc(krb5_storage *sp, off_t offset)
97 mem_storage *s = (mem_storage*)sp->data;
98 if(offset > s->size)
99 return ERANGE;
100 s->size = offset;
101 if ((s->ptr - s->base) > offset)
102 s->ptr = s->base + offset;
103 return 0;
106 static int
107 mem_no_trunc(krb5_storage *sp, off_t offset)
109 return EINVAL;
113 * Create a fixed size memory storage block
115 * @return A krb5_storage on success, or NULL on out of memory error.
117 * @ingroup krb5_storage
119 * @sa krb5_storage_mem()
120 * @sa krb5_storage_from_readonly_mem()
121 * @sa krb5_storage_from_data()
122 * @sa krb5_storage_from_fd()
125 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
126 krb5_storage_from_mem(void *buf, size_t len)
128 krb5_storage *sp = malloc(sizeof(krb5_storage));
129 mem_storage *s;
130 if(sp == NULL)
131 return NULL;
132 s = malloc(sizeof(*s));
133 if(s == NULL) {
134 free(sp);
135 return NULL;
137 sp->data = s;
138 sp->flags = 0;
139 sp->eof_code = HEIM_ERR_EOF;
140 s->base = buf;
141 s->size = len;
142 s->ptr = buf;
143 sp->fetch = mem_fetch;
144 sp->store = mem_store;
145 sp->seek = mem_seek;
146 sp->trunc = mem_trunc;
147 sp->free = NULL;
148 return sp;
152 * Create a fixed size memory storage block
154 * @return A krb5_storage on success, or NULL on out of memory error.
156 * @ingroup krb5_storage
158 * @sa krb5_storage_mem()
159 * @sa krb5_storage_from_mem()
160 * @sa krb5_storage_from_readonly_mem()
161 * @sa krb5_storage_from_fd()
164 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
165 krb5_storage_from_data(krb5_data *data)
167 return krb5_storage_from_mem(data->data, data->length);
171 * Create a fixed size memory storage block that is read only
173 * @return A krb5_storage on success, or NULL on out of memory error.
175 * @ingroup krb5_storage
177 * @sa krb5_storage_mem()
178 * @sa krb5_storage_from_mem()
179 * @sa krb5_storage_from_data()
180 * @sa krb5_storage_from_fd()
183 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
184 krb5_storage_from_readonly_mem(const void *buf, size_t len)
186 krb5_storage *sp = malloc(sizeof(krb5_storage));
187 mem_storage *s;
188 if(sp == NULL)
189 return NULL;
190 s = malloc(sizeof(*s));
191 if(s == NULL) {
192 free(sp);
193 return NULL;
195 sp->data = s;
196 sp->flags = 0;
197 sp->eof_code = HEIM_ERR_EOF;
198 s->base = rk_UNCONST(buf);
199 s->size = len;
200 s->ptr = rk_UNCONST(buf);
201 sp->fetch = mem_fetch;
202 sp->store = mem_no_store;
203 sp->seek = mem_seek;
204 sp->trunc = mem_no_trunc;
205 sp->free = NULL;
206 return sp;