/* * MiniVHD Minimalist VHD implementation in C. * * This file is part of the MiniVHD Project. * * Header and footer serialize/deserialize functions. * * Read data from footer into the struct members, swapping * endian where necessary. * * NOTE: Order matters here! * We must read each field in the order the struct is in. * Doing this may be less elegant than performing a memcpy * to a packed struct, but it avoids potential data alignment * issues, and the endian swapping allows us to use the fields * directly. * * Version: @(#)struct_rw.c 1.0.2 2021/04/16 * * Author: Sherman Perry, * * Copyright 2019-2021 Sherman Perry. * * MIT License * * Permission is hereby granted, free of charge, to any person * obtaining a copy of this software and associated documenta- * tion files (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, * copy, modify, merge, publish, distribute, sublicense, and/or * sell copies of the Software, and to permit persons to whom * the Software is furnished to do so, subject to the following * conditions: * * The above copyright notice and this permission notice shall * be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF O R IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ #ifndef _FILE_OFFSET_BITS # define _FILE_OFFSET_BITS 64 #endif #include #include #include #include #include #include #include "minivhd.h" #include "internal.h" /** * \brief Get the next field from a buffer and store it in a struct member, converting endian if necessary * * \param [out] struct_memb struct member to save the field to * \param [in] memb_size the size of struct_memb, in bytes * \param [in] req_endian is the field a value that requires endian conversion (eg: uint16, uint32) * \param [in] buffer the buffer from which fields are read from. Will be advanced at the end of the function call */ static void next_buffer_to_struct(void* struct_memb, size_t memb_size, bool req_endian, uint8_t** buffer) { memcpy(struct_memb, *buffer, memb_size); if (req_endian) switch (memb_size) { case 2: *(uint16_t*)(struct_memb) = mvhd_from_be16(*(uint16_t*)(struct_memb)); break; case 4: *(uint32_t*)(struct_memb) = mvhd_from_be32(*(uint32_t*)(struct_memb)); break; case 8: *(uint64_t*)(struct_memb) = mvhd_from_be64(*(uint64_t*)(struct_memb)); break; } *buffer += memb_size; } /** * \brief Save a struct member into a buffer, converting endian if necessary * * \param [in] struct_memb struct member read from * \param [in] memb_size the size of struct_memb, in bytes * \param [in] req_endian is the field a value that requires endian conversion (eg: uint16, uint32) * \param [out] buffer the buffer from which struct member is saved to. Will be advanced at the end of the function call */ static void next_struct_to_buffer(void* struct_memb, size_t memb_size, bool req_endian, uint8_t** buffer) { uint8_t *buf_ptr = *buffer; memcpy(buf_ptr, struct_memb, memb_size); if (req_endian) switch (memb_size) { case 2: *((uint16_t*)buf_ptr) = mvhd_to_be16(*(uint16_t*)(struct_memb)); break; case 4: *((uint32_t*)buf_ptr) = mvhd_to_be32(*(uint32_t*)(struct_memb)); break; case 8: *((uint64_t*)buf_ptr) = mvhd_to_be64(*(uint64_t*)(struct_memb)); break; } buf_ptr += memb_size; *buffer = buf_ptr; } void mvhd_buffer_to_footer(MVHDFooter* footer, uint8_t* buffer) { uint8_t* buff_ptr = buffer; next_buffer_to_struct(&footer->cookie, sizeof footer->cookie, false, &buff_ptr); next_buffer_to_struct(&footer->features, sizeof footer->features, true, &buff_ptr); next_buffer_to_struct(&footer->fi_fmt_vers, sizeof footer->fi_fmt_vers, true, &buff_ptr); next_buffer_to_struct(&footer->data_offset, sizeof footer->data_offset, true, &buff_ptr); next_buffer_to_struct(&footer->timestamp, sizeof footer->timestamp, true, &buff_ptr); next_buffer_to_struct(&footer->cr_app, sizeof footer->cr_app, false, &buff_ptr); next_buffer_to_struct(&footer->cr_vers, sizeof footer->cr_vers, true, &buff_ptr); next_buffer_to_struct(&footer->cr_host_os, sizeof footer->cr_host_os, false, &buff_ptr); next_buffer_to_struct(&footer->orig_sz, sizeof footer->orig_sz, true, &buff_ptr); next_buffer_to_struct(&footer->curr_sz, sizeof footer->curr_sz, true, &buff_ptr); next_buffer_to_struct(&footer->geom.cyl, sizeof footer->geom.cyl, true, &buff_ptr); next_buffer_to_struct(&footer->geom.heads, sizeof footer->geom.heads, false, &buff_ptr); next_buffer_to_struct(&footer->geom.spt, sizeof footer->geom.spt, false, &buff_ptr); next_buffer_to_struct(&footer->disk_type, sizeof footer->disk_type, true, &buff_ptr); next_buffer_to_struct(&footer->checksum, sizeof footer->checksum, true, &buff_ptr); next_buffer_to_struct(&footer->uuid, sizeof footer->uuid, false, &buff_ptr); next_buffer_to_struct(&footer->saved_st, sizeof footer->saved_st, false, &buff_ptr); next_buffer_to_struct(&footer->reserved, sizeof footer->reserved, false, &buff_ptr); } void mvhd_footer_to_buffer(MVHDFooter* footer, uint8_t* buffer) { uint8_t* buff_ptr = buffer; next_struct_to_buffer(&footer->cookie, sizeof footer->cookie, false, &buff_ptr); next_struct_to_buffer(&footer->features, sizeof footer->features, true, &buff_ptr); next_struct_to_buffer(&footer->fi_fmt_vers, sizeof footer->fi_fmt_vers, true, &buff_ptr); next_struct_to_buffer(&footer->data_offset, sizeof footer->data_offset, true, &buff_ptr); next_struct_to_buffer(&footer->timestamp, sizeof footer->timestamp, true, &buff_ptr); next_struct_to_buffer(&footer->cr_app, sizeof footer->cr_app, false, &buff_ptr); next_struct_to_buffer(&footer->cr_vers, sizeof footer->cr_vers, true, &buff_ptr); next_struct_to_buffer(&footer->cr_host_os, sizeof footer->cr_host_os, false, &buff_ptr); next_struct_to_buffer(&footer->orig_sz, sizeof footer->orig_sz, true, &buff_ptr); next_struct_to_buffer(&footer->curr_sz, sizeof footer->curr_sz, true, &buff_ptr); next_struct_to_buffer(&footer->geom.cyl, sizeof footer->geom.cyl, true, &buff_ptr); next_struct_to_buffer(&footer->geom.heads, sizeof footer->geom.heads, false, &buff_ptr); next_struct_to_buffer(&footer->geom.spt, sizeof footer->geom.spt, false, &buff_ptr); next_struct_to_buffer(&footer->disk_type, sizeof footer->disk_type, true, &buff_ptr); next_struct_to_buffer(&footer->checksum, sizeof footer->checksum, true, &buff_ptr); next_struct_to_buffer(&footer->uuid, sizeof footer->uuid, false, &buff_ptr); next_struct_to_buffer(&footer->saved_st, sizeof footer->saved_st, false, &buff_ptr); next_struct_to_buffer(&footer->reserved, sizeof footer->reserved, false, &buff_ptr); } void mvhd_buffer_to_header(MVHDSparseHeader* header, uint8_t* buffer) { uint8_t* buff_ptr = buffer; next_buffer_to_struct(&header->cookie, sizeof header->cookie, false, &buff_ptr); next_buffer_to_struct(&header->data_offset, sizeof header->data_offset, true, &buff_ptr); next_buffer_to_struct(&header->bat_offset, sizeof header->bat_offset, true, &buff_ptr); next_buffer_to_struct(&header->head_vers, sizeof header->head_vers, true, &buff_ptr); next_buffer_to_struct(&header->max_bat_ent, sizeof header->max_bat_ent, true, &buff_ptr); next_buffer_to_struct(&header->block_sz, sizeof header->block_sz, true, &buff_ptr); next_buffer_to_struct(&header->checksum, sizeof header->checksum, true, &buff_ptr); next_buffer_to_struct(&header->par_uuid, sizeof header->par_uuid, false, &buff_ptr); next_buffer_to_struct(&header->par_timestamp, sizeof header->par_timestamp, true, &buff_ptr); next_buffer_to_struct(&header->reserved_1, sizeof header->reserved_1, true, &buff_ptr); next_buffer_to_struct(&header->par_utf16_name, sizeof header->par_utf16_name, false, &buff_ptr); for (int i = 0; i < 8; i++) { next_buffer_to_struct(&header->par_loc_entry[i].plat_code, sizeof header->par_loc_entry[i].plat_code, true, &buff_ptr); next_buffer_to_struct(&header->par_loc_entry[i].plat_data_space, sizeof header->par_loc_entry[i].plat_data_space, true, &buff_ptr); next_buffer_to_struct(&header->par_loc_entry[i].plat_data_len, sizeof header->par_loc_entry[i].plat_data_len, true, &buff_ptr); next_buffer_to_struct(&header->par_loc_entry[i].reserved, sizeof header->par_loc_entry[i].reserved, true, &buff_ptr); next_buffer_to_struct(&header->par_loc_entry[i].plat_data_offset, sizeof header->par_loc_entry[i].plat_data_offset, true, &buff_ptr); } next_buffer_to_struct(&header->reserved_2, sizeof header->reserved_2, false, &buff_ptr); } void mvhd_header_to_buffer(MVHDSparseHeader* header, uint8_t* buffer) { uint8_t* buff_ptr = buffer; next_struct_to_buffer(&header->cookie, sizeof header->cookie, false, &buff_ptr); next_struct_to_buffer(&header->data_offset, sizeof header->data_offset, true, &buff_ptr); next_struct_to_buffer(&header->bat_offset, sizeof header->bat_offset, true, &buff_ptr); next_struct_to_buffer(&header->head_vers, sizeof header->head_vers, true, &buff_ptr); next_struct_to_buffer(&header->max_bat_ent, sizeof header->max_bat_ent, true, &buff_ptr); next_struct_to_buffer(&header->block_sz, sizeof header->block_sz, true, &buff_ptr); next_struct_to_buffer(&header->checksum, sizeof header->checksum, true, &buff_ptr); next_struct_to_buffer(&header->par_uuid, sizeof header->par_uuid, false, &buff_ptr); next_struct_to_buffer(&header->par_timestamp, sizeof header->par_timestamp, true, &buff_ptr); next_struct_to_buffer(&header->reserved_1, sizeof header->reserved_1, true, &buff_ptr); next_struct_to_buffer(&header->par_utf16_name, sizeof header->par_utf16_name, false, &buff_ptr); for (int i = 0; i < 8; i++) { next_struct_to_buffer(&header->par_loc_entry[i].plat_code, sizeof header->par_loc_entry[i].plat_code, true, &buff_ptr); next_struct_to_buffer(&header->par_loc_entry[i].plat_data_space, sizeof header->par_loc_entry[i].plat_data_space, true, &buff_ptr); next_struct_to_buffer(&header->par_loc_entry[i].plat_data_len, sizeof header->par_loc_entry[i].plat_data_len, true, &buff_ptr); next_struct_to_buffer(&header->par_loc_entry[i].reserved, sizeof header->par_loc_entry[i].reserved, true, &buff_ptr); next_struct_to_buffer(&header->par_loc_entry[i].plat_data_offset, sizeof header->par_loc_entry[i].plat_data_offset, true, &buff_ptr); } next_struct_to_buffer(&header->reserved_2, sizeof header->reserved_2, false, &buff_ptr); }