store_emem.c revision 1.1
1265236Sken/* $NetBSD: store_emem.c,v 1.1 2011/04/13 18:15:38 elric Exp $ */ 2283990Sslm 3299962Sslm/* 4265236Sken * Copyright (c) 1997 - 2002 Kungliga Tekniska H��gskolan 5265236Sken * (Royal Institute of Technology, Stockholm, Sweden). 6265236Sken * All rights reserved. 7265236Sken * 8265236Sken * Redistribution and use in source and binary forms, with or without 9265236Sken * modification, are permitted provided that the following conditions 10265236Sken * are met: 11265236Sken * 12265236Sken * 1. Redistributions of source code must retain the above copyright 13265236Sken * notice, this list of conditions and the following disclaimer. 14265236Sken * 15265236Sken * 2. Redistributions in binary form must reproduce the above copyright 16265236Sken * notice, this list of conditions and the following disclaimer in the 17265236Sken * documentation and/or other materials provided with the distribution. 18265236Sken * 19265236Sken * 3. Neither the name of the Institute nor the names of its contributors 20265236Sken * may be used to endorse or promote products derived from this software 21265236Sken * without specific prior written permission. 22265236Sken * 23265236Sken * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24265236Sken * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25265236Sken * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26265236Sken * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27265236Sken * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28265236Sken * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29265236Sken * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30283990Sslm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31265236Sken * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32265236Sken * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33265236Sken * SUCH DAMAGE. 34265236Sken */ 35265236Sken 36283990Sslm#include "krb5_locl.h" 37299962Sslm#include "store-int.h" 38299962Sslm 39265236Skentypedef struct emem_storage{ 40265236Sken unsigned char *base; 41265236Sken size_t size; 42265236Sken size_t len; 43265236Sken unsigned char *ptr; 44265236Sken}emem_storage; 45299962Sslm 46265236Skenstatic ssize_t 47265236Skenemem_fetch(krb5_storage *sp, void *data, size_t size) 48265236Sken{ 49265236Sken emem_storage *s = (emem_storage*)sp->data; 50265236Sken if(s->base + s->len - s->ptr < size) 51265236Sken size = s->base + s->len - s->ptr; 52265236Sken memmove(data, s->ptr, size); 53299962Sslm sp->seek(sp, size, SEEK_CUR); 54265236Sken return size; 55265236Sken} 56265236Sken 57265236Skenstatic ssize_t 58265236Skenemem_store(krb5_storage *sp, const void *data, size_t size) 59265236Sken{ 60265236Sken emem_storage *s = (emem_storage*)sp->data; 61265236Sken if(size > s->base + s->size - s->ptr){ 62265236Sken void *base; 63265236Sken size_t sz, off; 64265236Sken off = s->ptr - s->base; 65265236Sken sz = off + size; 66265236Sken if (sz < 4096) 67265236Sken sz *= 2; 68265236Sken base = realloc(s->base, sz); 69265236Sken if(base == NULL) 70265236Sken return -1; 71265236Sken s->size = sz; 72265236Sken s->base = base; 73265236Sken s->ptr = (unsigned char*)base + off; 74265236Sken } 75265236Sken memmove(s->ptr, data, size); 76265236Sken sp->seek(sp, size, SEEK_CUR); 77265236Sken return size; 78265236Sken} 79265236Sken 80265236Skenstatic off_t 81265236Skenemem_seek(krb5_storage *sp, off_t offset, int whence) 82265236Sken{ 83265236Sken emem_storage *s = (emem_storage*)sp->data; 84265236Sken switch(whence){ 85265236Sken case SEEK_SET: 86265236Sken if(offset > s->size) 87265236Sken offset = s->size; 88265236Sken if(offset < 0) 89265236Sken offset = 0; 90265236Sken s->ptr = s->base + offset; 91265236Sken if(offset > s->len) 92265236Sken s->len = offset; 93265236Sken break; 94265236Sken case SEEK_CUR: 95265236Sken sp->seek(sp,s->ptr - s->base + offset, SEEK_SET); 96265236Sken break; 97265236Sken case SEEK_END: 98265236Sken sp->seek(sp, s->len + offset, SEEK_SET); 99265236Sken break; 100265236Sken default: 101265236Sken errno = EINVAL; 102265236Sken return -1; 103265236Sken } 104265236Sken return s->ptr - s->base; 105265236Sken} 106265236Sken 107265236Skenstatic int 108265236Skenemem_trunc(krb5_storage *sp, off_t offset) 109265236Sken{ 110265236Sken emem_storage *s = (emem_storage*)sp->data; 111265236Sken /* 112265236Sken * If offset is larget then current size, or current size is 113265236Sken * shrunk more then half of the current size, adjust buffer. 114265236Sken */ 115265236Sken if (offset == 0) { 116265236Sken free(s->base); 117265236Sken s->size = 0; 118265236Sken s->base = NULL; 119265236Sken s->ptr = NULL; 120265236Sken } else if (offset > s->size || (s->size / 2) > offset) { 121265236Sken void *base; 122265236Sken size_t off; 123265236Sken off = s->ptr - s->base; 124265236Sken base = realloc(s->base, offset); 125265236Sken if(base == NULL) 126265236Sken return ENOMEM; 127265236Sken if (offset > s->size) 128265236Sken memset((char *)base + s->size, 0, offset - s->size); 129265236Sken s->size = offset; 130265236Sken s->base = base; 131265236Sken s->ptr = (unsigned char *)base + off; 132265236Sken } 133265236Sken s->len = offset; 134265236Sken if ((s->ptr - s->base) > offset) 135265236Sken s->ptr = s->base + offset; 136 return 0; 137} 138 139 140static void 141emem_free(krb5_storage *sp) 142{ 143 emem_storage *s = sp->data; 144 memset(s->base, 0, s->len); 145 free(s->base); 146} 147 148/** 149 * Create a elastic (allocating) memory storage backend. Memory is 150 * allocated on demand. Free returned krb5_storage with 151 * krb5_storage_free(). 152 * 153 * @return A krb5_storage on success, or NULL on out of memory error. 154 * 155 * @ingroup krb5_storage 156 * 157 * @sa krb5_storage_from_mem() 158 * @sa krb5_storage_from_readonly_mem() 159 * @sa krb5_storage_from_fd() 160 * @sa krb5_storage_from_data() 161 */ 162 163KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL 164krb5_storage_emem(void) 165{ 166 krb5_storage *sp; 167 emem_storage *s; 168 169 sp = malloc(sizeof(krb5_storage)); 170 if (sp == NULL) 171 return NULL; 172 173 s = malloc(sizeof(*s)); 174 if (s == NULL) { 175 free(sp); 176 return NULL; 177 } 178 sp->data = s; 179 sp->flags = 0; 180 sp->eof_code = HEIM_ERR_EOF; 181 s->size = 1024; 182 s->base = malloc(s->size); 183 if (s->base == NULL) { 184 free(sp); 185 free(s); 186 return NULL; 187 } 188 s->len = 0; 189 s->ptr = s->base; 190 sp->fetch = emem_fetch; 191 sp->store = emem_store; 192 sp->seek = emem_seek; 193 sp->trunc = emem_trunc; 194 sp->free = emem_free; 195 return sp; 196} 197