1 /* 2 * Copyright (c) 1997 - 2002 Kungliga Tekniska H�gskolan 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: store_emem.c,v 1.13 2002/10/21 15:36:23 joda Exp $"); 38 39 typedef struct emem_storage{ 40 unsigned char *base; 41 size_t size; 42 size_t len; 43 unsigned char *ptr; 44 }emem_storage; 45 46 static ssize_t 47 emem_fetch(krb5_storage *sp, void *data, size_t size) 48 { 49 emem_storage *s = (emem_storage*)sp->data; 50 if(s->base + s->len - s->ptr < size) 51 size = s->base + s->len - s->ptr; 52 memmove(data, s->ptr, size); 53 sp->seek(sp, size, SEEK_CUR); 54 return size; 55 } 56 57 static ssize_t 58 emem_store(krb5_storage *sp, const void *data, size_t size) 59 { 60 emem_storage *s = (emem_storage*)sp->data; 61 if(size > s->base + s->size - s->ptr){ 62 void *base; 63 size_t sz, off; 64 off = s->ptr - s->base; 65 sz = off + size; 66 if (sz < 4096) 67 sz *= 2; 68 base = realloc(s->base, sz); 69 if(base == NULL) 70 return 0; 71 s->size = sz; 72 s->base = base; 73 s->ptr = (unsigned char*)base + off; 74 } 75 memmove(s->ptr, data, size); 76 sp->seek(sp, size, SEEK_CUR); 77 return size; 78 } 79 80 static off_t 81 emem_seek(krb5_storage *sp, off_t offset, int whence) 82 { 83 emem_storage *s = (emem_storage*)sp->data; 84 switch(whence){ 85 case SEEK_SET: 86 if(offset > s->size) 87 offset = s->size; 88 if(offset < 0) 89 offset = 0; 90 s->ptr = s->base + offset; 91 if(offset > s->len) 92 s->len = offset; 93 break; 94 case SEEK_CUR: 95 sp->seek(sp,s->ptr - s->base + offset, SEEK_SET); 96 break; 97 case SEEK_END: 98 sp->seek(sp, s->len + offset, SEEK_SET); 99 break; 100 default: 101 errno = EINVAL; 102 return -1; 103 } 104 return s->ptr - s->base; 105 } 106 107 static void 108 emem_free(krb5_storage *sp) 109 { 110 emem_storage *s = sp->data; 111 memset(s->base, 0, s->len); 112 free(s->base); 113 } 114 115 krb5_storage * 116 krb5_storage_emem(void) 117 { 118 krb5_storage *sp = malloc(sizeof(krb5_storage)); 119 emem_storage *s = malloc(sizeof(*s)); 120 sp->data = s; 121 sp->flags = 0; 122 sp->eof_code = HEIM_ERR_EOF; 123 s->size = 1024; 124 s->base = malloc(s->size); 125 s->len = 0; 126 s->ptr = s->base; 127 sp->fetch = emem_fetch; 128 sp->store = emem_store; 129 sp->seek = emem_seek; 130 sp->free = emem_free; 131 return sp; 132 } 133