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 RCSID("$Id$");
  38
  39 typedef struct mem_storage{
  40     unsigned char *base;
  41     size_t size;
  42     unsigned char *ptr;
  43 }mem_storage;
  44
  45 static ssize_t
  46 mem_fetch(krb5_storage *sp, void *data, size_t size)
  47 {
  48     mem_storage *s = (mem_storage*)sp->data;
  49     if(size > s->base + s->size - s->ptr)
  50         size = s->base + s->size - s->ptr;
  51     memmove(data, s->ptr, size);
  52     sp->seek(sp, size, SEEK_CUR);
  53     return size;
  54 }
  55
  56 static ssize_t
  57 mem_store(krb5_storage *sp, const void *data, size_t size)
  58 {
  59     mem_storage *s = (mem_storage*)sp->data;
  60     if(size > s->base + s->size - s->ptr)
  61         size = s->base + s->size - s->ptr;
  62     memmove(s->ptr, data, size);
  63     sp->seek(sp, size, SEEK_CUR);
  64     return size;
  65 }
  66
  67 static ssize_t
  68 mem_no_store(krb5_storage *sp, const void *data, size_t size)
  69 {
  70     return -1;
  71 }
  72
  73 static off_t
  74 mem_seek(krb5_storage *sp, off_t offset, int whence)
  75 {
  76     mem_storage *s = (mem_storage*)sp->data;
  77     switch(whence){
  78     case SEEK_SET:
  79         if(offset > s->size)
  80             offset = s->size;
  81         if(offset < 0)
  82             offset = 0;
  83         s->ptr = s->base + offset;
  84         break;
  85     case SEEK_CUR:
  86         return sp->seek(sp, s->ptr - s->base + offset, SEEK_SET);
  87     case SEEK_END:
  88         return sp->seek(sp, s->size + offset, SEEK_SET);
  89     default:
  90         errno = EINVAL;
  91         return -1;
  92     }
  93     return s->ptr - s->base;
  94 }
  95
  96 krb5_storage * KRB5_LIB_FUNCTION
  97 krb5_storage_from_mem(void *buf, size_t len)
  98 {
  99     krb5_storage *sp = malloc(sizeof(krb5_storage));
 100     mem_storage *s;
 101     if(sp == NULL)
 102         return NULL;
 103     s = malloc(sizeof(*s));
 104     if(s == NULL) {
 105         free(sp);
 106         return NULL;
 107     }
 108     sp->data = s;
 109     sp->flags = 0;
 110     sp->eof_code = HEIM_ERR_EOF;
 111     s->base = buf;
 112     s->size = len;
 113     s->ptr = buf;
 114     sp->fetch = mem_fetch;
 115     sp->store = mem_store;
 116     sp->seek = mem_seek;
 117     sp->free = NULL;
 118     return sp;
 119 }
 120
 121 krb5_storage * KRB5_LIB_FUNCTION
 122 krb5_storage_from_data(krb5_data *data)
 123 {
 124     return krb5_storage_from_mem(data->data, data->length);
 125 }
 126
 127 krb5_storage * KRB5_LIB_FUNCTION
 128 krb5_storage_from_readonly_mem(const void *buf, size_t len)
 129 {
 130     krb5_storage *sp = malloc(sizeof(krb5_storage));
 131     mem_storage *s;
 132     if(sp == NULL)
 133         return NULL;
 134     s = malloc(sizeof(*s));
 135     if(s == NULL) {
 136         free(sp);
 137         return NULL;
 138     }
 139     sp->data = s;
 140     sp->flags = 0;
 141     sp->eof_code = HEIM_ERR_EOF;
 142     s->base = rk_UNCONST(buf);
 143     s->size = len;
 144     s->ptr = rk_UNCONST(buf);
 145     sp->fetch = mem_fetch;
 146     sp->store = mem_no_store;
 147     sp->seek = mem_seek;
 148     sp->free = NULL;
 149     return sp;
 150 }