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 1.12 2002/04/18 14:00:34 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 sz = 2 * (size + (s->ptr - s->base)); /* XXX */ 65 off = s->ptr - s->base; 66 base = realloc(s->base, sz); 67 if(base == NULL) 68 return 0; 69 s->size = sz; 70 s->base = base; 71 s->ptr = (unsigned char*)base + off; 72 } 73 memmove(s->ptr, data, size); 74 sp->seek(sp, size, SEEK_CUR); 75 return size; 76 } 77 78 static off_t 79 emem_seek(krb5_storage *sp, off_t offset, int whence) 80 { 81 emem_storage *s = (emem_storage*)sp->data; 82 switch(whence){ 83 case SEEK_SET: 84 if(offset > s->size) 85 offset = s->size; 86 if(offset < 0) 87 offset = 0; 88 s->ptr = s->base + offset; 89 if(offset > s->len) 90 s->len = offset; 91 break; 92 case SEEK_CUR: 93 sp->seek(sp,s->ptr - s->base + offset, SEEK_SET); 94 break; 95 case SEEK_END: 96 sp->seek(sp, s->len + offset, SEEK_SET); 97 break; 98 default: 99 errno = EINVAL; 100 return -1; 101 } 102 return s->ptr - s->base; 103 } 104 105 static void 106 emem_free(krb5_storage *sp) 107 { 108 emem_storage *s = sp->data; 109 memset(s->base, 0, s->len); 110 free(s->base); 111 } 112 113 krb5_storage * 114 krb5_storage_emem(void) 115 { 116 krb5_storage *sp = malloc(sizeof(krb5_storage)); 117 emem_storage *s = malloc(sizeof(*s)); 118 sp->data = s; 119 sp->flags = 0; 120 sp->eof_code = HEIM_ERR_EOF; 121 s->size = 1024; 122 s->base = malloc(s->size); 123 s->len = 0; 124 s->ptr = s->base; 125 sp->fetch = emem_fetch; 126 sp->store = emem_store; 127 sp->seek = emem_seek; 128 sp->free = emem_free; 129 return sp; 130 } 131