lib/krb5/store_mem.c

   1 /*
   2  * Copyright (c) 1997 - 2000, 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
  37 typedef struct mem_storage{
  38     unsigned char *base;
  39     size_t size;
  40     unsigned char *ptr;
  41 }mem_storage;
  42
  43 static ssize_t
  44 mem_fetch(krb5_storage *sp, void *data, size_t size)
  45 {
  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;
  52 }
  53
  54 static ssize_t
  55 mem_store(krb5_storage *sp, const void *data, size_t size)
  56 {
  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;
  63 }
  64
  65 static ssize_t
  66 mem_no_store(krb5_storage *sp, const void *data, size_t size)
  67 {
  68     return -1;
  69 }
  70
  71 static off_t
  72 mem_seek(krb5_storage *sp, off_t offset, int whence)
  73 {
  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;
  90     }
  91     return s->ptr - s->base;
  92 }
  93
  94 static int
  95 mem_trunc(krb5_storage *sp, off_t offset)
  96 {
  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;
 104 }
 105
 106 static int
 107 mem_no_trunc(krb5_storage *sp, off_t offset)
 108 {
 109     return EINVAL;
 110 }
 111
 112 /**
 113  * Create a fixed size memory storage block
 114  *
 115  * @return A krb5_storage on success, or NULL on out of memory error.
 116  *
 117  * @ingroup krb5_storage
 118  *
 119  * @sa krb5_storage_mem()
 120  * @sa krb5_storage_from_readonly_mem()
 121  * @sa krb5_storage_from_data()
 122  * @sa krb5_storage_from_fd()
 123  */
 124
 125 krb5_storage * KRB5_LIB_FUNCTION
 126 krb5_storage_from_mem(void *buf, size_t len)
 127 {
 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;
 136     }
 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;
 149 }
 150
 151 /**
 152  * Create a fixed size memory storage block
 153  *
 154  * @return A krb5_storage on success, or NULL on out of memory error.
 155  *
 156  * @ingroup krb5_storage
 157  *
 158  * @sa krb5_storage_mem()
 159  * @sa krb5_storage_from_mem()
 160  * @sa krb5_storage_from_readonly_mem()
 161  * @sa krb5_storage_from_fd()
 162  */
 163
 164 krb5_storage * KRB5_LIB_FUNCTION
 165 krb5_storage_from_data(krb5_data *data)
 166 {
 167     return krb5_storage_from_mem(data->data, data->length);
 168 }
 169
 170 /**
 171  * Create a fixed size memory storage block that is read only
 172  *
 173  * @return A krb5_storage on success, or NULL on out of memory error.
 174  *
 175  * @ingroup krb5_storage
 176  *
 177  * @sa krb5_storage_mem()
 178  * @sa krb5_storage_from_mem()
 179  * @sa krb5_storage_from_data()
 180  * @sa krb5_storage_from_fd()
 181  */
 182
 183 krb5_storage * KRB5_LIB_FUNCTION
 184 krb5_storage_from_readonly_mem(const void *buf, size_t len)
 185 {
 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;
 194     }
 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;
 207 }