176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman/* ----------------------------------------------------------------------- * 276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * Copyright 2007-2008 H. Peter Anvin - All Rights Reserved 476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * Copyright 2009 Intel Corporation; author: H. Peter Anvin 576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * Permission is hereby granted, free of charge, to any person 776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * obtaining a copy of this software and associated documentation 876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * files (the "Software"), to deal in the Software without 976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * restriction, including without limitation the rights to use, 1076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * copy, modify, merge, publish, distribute, sublicense, and/or 1176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * sell copies of the Software, and to permit persons to whom 1276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * the Software is furnished to do so, subject to the following 1376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * conditions: 1476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 1576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * The above copyright notice and this permission notice shall 1676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * be included in all copies or substantial portions of the Software. 1776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 1876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 1976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 2076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 2176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 2276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 2376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 2476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 2576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * OTHER DEALINGS IN THE SOFTWARE. 2676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 2776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * ----------------------------------------------------------------------- */ 2876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 2976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman/* 3076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * syslinux/setadv.c 3176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 3276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * (Over)write a data item in the auxilliary data vector. To 3376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * delete an item, set its length to zero. 3476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 3576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * Return 0 on success, -1 on error, and set errno. 3676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * 3776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * NOTE: Data is not written to disk unless 3876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman * syslinux_adv_write() is called. 3976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman */ 4076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 4176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <syslinux/adv.h> 4276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <klibc/compiler.h> 4376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <inttypes.h> 4476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <string.h> 4576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <errno.h> 4676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman#include <alloca.h> 4776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 4876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman__export int syslinux_setadv(int tag, size_t size, const void *data) 4976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman{ 5076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman uint8_t *p, *advtmp; 5176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman size_t rleft, left; 5276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 5376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if ((unsigned)tag - 1 > 254) { 5476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman errno = EINVAL; 5576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman return -1; /* Impossible tag value */ 5676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } 5776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 5876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if (size > 255) { 5976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman errno = ENOSPC; /* Max 255 bytes for a data item */ 6076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman return -1; 6176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } 6276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 6376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman rleft = left = syslinux_adv_size(); 6476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman p = advtmp = alloca(left); 6576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman memcpy(p, syslinux_adv_ptr(), left); /* Make working copy */ 6676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 6776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman while (rleft >= 2) { 6876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman uint8_t ptag = p[0]; 6976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman size_t plen = p[1] + 2; 7076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 7176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if (ptag == ADV_END) 7276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman break; 7376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 7476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if (ptag == tag) { 7576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman /* Found our tag. Delete it. */ 7676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 7776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if (plen >= rleft) { 7876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman /* Entire remainder is our tag */ 7976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman break; 8076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } 8176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman memmove(p, p + plen, rleft - plen); 8276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman rleft -= plen; /* Fewer bytes to read, but not to write */ 8376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } else { 8476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman /* Not our tag */ 8576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if (plen > rleft) 8676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman break; /* Corrupt tag (overrun) - overwrite it */ 8776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 8876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman left -= plen; 8976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman rleft -= plen; 9076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman p += plen; 9176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } 9276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } 9376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 9476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman /* Now (p, left) reflects the position to write in and how much space 9576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman we have for our data. */ 9676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 9776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if (size) { 9876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman if (left < size + 2) { 9976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman errno = ENOSPC; /* Not enough space for data */ 10076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman return -1; 10176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } 10276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 10376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman *p++ = tag; 10476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman *p++ = size; 10576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman memcpy(p, data, size); 10676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman p += size; 10776d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman left -= size + 2; 10876d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman } 10976d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 11076d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman memset(p, 0, left); 11176d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 11276d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman /* If we got here, everything went OK, commit the write to low memory */ 11376d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman memcpy(syslinux_adv_ptr(), advtmp, syslinux_adv_size()); 11476d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman 11576d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman return 0; 11676d05dc695b06c4e987bb8078f78032441e1430cGreg Hartman} 117