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 > (size_t)(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 > (size_t)(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((size_t)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((size_t)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  * @sa krb5_storage_from_socket()
 124  */
 125
 126 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
 127 krb5_storage_from_mem(void *buf, size_t len)
 128 {
 129     krb5_storage *sp = malloc(sizeof(krb5_storage));
 130     mem_storage *s;
 131     if(sp == NULL)
 132         return NULL;
 133     s = malloc(sizeof(*s));
 134     if(s == NULL) {
 135         free(sp);
 136         return NULL;
 137     }
 138     sp->data = s;
 139     sp->flags = 0;
 140     sp->eof_code = HEIM_ERR_EOF;
 141     s->base = buf;
 142     s->size = len;
 143     s->ptr = buf;
 144     sp->fetch = mem_fetch;
 145     sp->store = mem_store;
 146     sp->seek = mem_seek;
 147     sp->trunc = mem_trunc;
 148     sp->fsync = NULL;
 149     sp->free = NULL;
 150     sp->max_alloc = UINT_MAX/8;
 151     return sp;
 152 }
 153
 154 /**
 155  * Create a fixed size memory storage block
 156  *
 157  * @return A krb5_storage on success, or NULL on out of memory error.
 158  *
 159  * @ingroup krb5_storage
 160  *
 161  * @sa krb5_storage_mem()
 162  * @sa krb5_storage_from_mem()
 163  * @sa krb5_storage_from_readonly_mem()
 164  * @sa krb5_storage_from_fd()
 165  */
 166
 167 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
 168 krb5_storage_from_data(krb5_data *data)
 169 {
 170     return krb5_storage_from_mem(data->data, data->length);
 171 }
 172
 173 /**
 174  * Create a fixed size memory storage block that is read only
 175  *
 176  * @return A krb5_storage on success, or NULL on out of memory error.
 177  *
 178  * @ingroup krb5_storage
 179  *
 180  * @sa krb5_storage_mem()
 181  * @sa krb5_storage_from_mem()
 182  * @sa krb5_storage_from_data()
 183  * @sa krb5_storage_from_fd()
 184  */
 185
 186 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
 187 krb5_storage_from_readonly_mem(const void *buf, size_t len)
 188 {
 189     krb5_storage *sp = malloc(sizeof(krb5_storage));
 190     mem_storage *s;
 191     if(sp == NULL)
 192         return NULL;
 193     s = malloc(sizeof(*s));
 194     if(s == NULL) {
 195         free(sp);
 196         return NULL;
 197     }
 198     sp->data = s;
 199     sp->flags = 0;
 200     sp->eof_code = HEIM_ERR_EOF;
 201     s->base = rk_UNCONST(buf);
 202     s->size = len;
 203     s->ptr = rk_UNCONST(buf);
 204     sp->fetch = mem_fetch;
 205     sp->store = mem_no_store;
 206     sp->seek = mem_seek;
 207     sp->trunc = mem_no_trunc;
 208     sp->fsync = NULL;
 209     sp->free = NULL;
 210     sp->max_alloc = UINT_MAX/8;
 211     return sp;
 212 }