| /* |
| * This file is part of the libpayload project. |
| * |
| * Copyright (C) 2011 secunet Security Networks AG |
| * Copyright (C) 2013 Google, Inc. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| /* The CBFS core requires a couple of #defines or functions to adapt it to the |
| * target environment: |
| * |
| * CBFS_CORE_WITH_LZMA (must be #define) |
| * if defined, ulzma() must exist for decompression of data streams |
| * |
| * ERROR(x...) |
| * print an error message x (in printf format) |
| * |
| * LOG(x...) |
| * print a message x (in printf format) |
| * |
| * DEBUG(x...) |
| * print a debug message x (in printf format) |
| * |
| */ |
| |
| #include <cbfs.h> |
| #include <string.h> |
| |
| /* returns a pointer to CBFS master header, or CBFS_HEADER_INVALID_ADDRESS |
| * on failure */ |
| const struct cbfs_header *cbfs_get_header(struct cbfs_media *media) |
| { |
| int32_t rel_offset; |
| const struct cbfs_header *header; |
| struct cbfs_media default_media; |
| |
| if (media == CBFS_DEFAULT_MEDIA) { |
| media = &default_media; |
| if (init_default_cbfs_media(media) != 0) { |
| ERROR("Failed to initialize default media.\n"); |
| return CBFS_HEADER_INVALID_ADDRESS; |
| } |
| } |
| media->open(media); |
| |
| if (!media->read(media, &rel_offset, (size_t)(0 - sizeof(int32_t)), |
| sizeof(int32_t))) { |
| ERROR("Could not read CBFS master header offset!\n"); |
| return CBFS_HEADER_INVALID_ADDRESS; |
| } |
| header = media->map(media, (size_t)rel_offset, sizeof(*header)); |
| DEBUG("CBFS header at %#zx (-%#zx from end of image).\n", |
| (size_t)rel_offset, (size_t)-rel_offset); |
| media->close(media); |
| |
| if (header == CBFS_MEDIA_INVALID_MAP_ADDRESS) { |
| ERROR("Failed to load CBFS header from %#zx(-%#zx)\n", |
| (size_t)rel_offset, (size_t)-rel_offset); |
| return CBFS_HEADER_INVALID_ADDRESS; |
| } |
| |
| if (CBFS_HEADER_MAGIC != ntohl(header->magic)) { |
| ERROR("Could not find valid CBFS master header at %#zx(-%#zx): " |
| "magic %#.8x vs %#.8x.\n", (size_t)rel_offset, |
| (size_t)-rel_offset, CBFS_HEADER_MAGIC, |
| ntohl(header->magic)); |
| if (header->magic == 0xffffffff) { |
| ERROR("Maybe ROM is not mapped properly?\n"); |
| } |
| return CBFS_HEADER_INVALID_ADDRESS; |
| } |
| return header; |
| } |
| |
| /* public API starts here*/ |
| struct cbfs_file *cbfs_get_file(struct cbfs_media *media, const char *name) |
| { |
| const char *vardata; |
| uint32_t offset, romsize, vardata_len; |
| const struct cbfs_header *header; |
| struct cbfs_file file, *file_ptr; |
| struct cbfs_media default_media; |
| |
| if (media == CBFS_DEFAULT_MEDIA) { |
| media = &default_media; |
| if (init_default_cbfs_media(media) != 0) { |
| ERROR("Failed to initialize default media.\n"); |
| return NULL; |
| } |
| } |
| |
| if (CBFS_HEADER_INVALID_ADDRESS == (header = cbfs_get_header(media))) |
| return NULL; |
| |
| // Logical offset (for source media) of first file. |
| offset = ntohl(header->offset); |
| romsize = ntohl(header->romsize); |
| |
| // TODO Add a "size" in CBFS header for a platform independent way to |
| // determine the end of CBFS data. |
| #if IS_ENABLED(CONFIG_LP_ARCH_X86) |
| // resolve actual length of ROM used for CBFS components |
| // the bootblock size was not taken into account |
| romsize -= ntohl(header->bootblocksize); |
| |
| // fine tune the length to handle alignment positioning. |
| // using (bootblock size) % align, to derive the |
| // number of bytes the bootblock is off from the alignment size. |
| if ((ntohl(header->bootblocksize) % CBFS_ALIGNMENT)) |
| romsize -= (CBFS_ALIGNMENT - |
| (ntohl(header->bootblocksize) % CBFS_ALIGNMENT)); |
| else |
| romsize -= 1; |
| #endif |
| |
| DEBUG("CBFS location: 0x%x~0x%x\n", offset, romsize); |
| DEBUG("Looking for '%s' starting from 0x%x.\n", name, offset); |
| |
| media->open(media); |
| while (offset < romsize && |
| media->read(media, &file, offset, sizeof(file)) == sizeof(file)) { |
| if (memcmp(CBFS_FILE_MAGIC, file.magic, |
| sizeof(file.magic)) != 0) { |
| uint32_t new_align = CBFS_ALIGNMENT; |
| if (offset % CBFS_ALIGNMENT) |
| new_align += CBFS_ALIGNMENT - |
| (offset % CBFS_ALIGNMENT); |
| ERROR("ERROR: No file header found at 0x%xx - " |
| "try next aligned address: 0x%x.\n", offset, |
| offset + new_align); |
| offset += new_align; |
| continue; |
| } |
| vardata_len = ntohl(file.offset) - sizeof(file); |
| DEBUG(" - load entry 0x%x variable data (%d bytes)...\n", |
| offset, vardata_len); |
| |
| // load file name (arbitrary length). |
| vardata = (const char*)media->map( |
| media, offset + sizeof(file), vardata_len); |
| if (vardata == CBFS_MEDIA_INVALID_MAP_ADDRESS) { |
| ERROR("ERROR: Failed to get filename: 0x%x.\n", offset); |
| } else if (strcmp(vardata, name) == 0) { |
| int file_offset = ntohl(file.offset), |
| file_len = ntohl(file.len); |
| DEBUG("Found file (offset=0x%x, len=%d).\n", |
| offset + file_offset, file_len); |
| media->unmap(media, vardata); |
| file_ptr = media->map(media, offset, |
| file_offset + file_len); |
| media->close(media); |
| return file_ptr; |
| } else { |
| DEBUG(" (unmatched file @0x%x: %s)\n", offset, |
| vardata); |
| media->unmap(media, vardata); |
| } |
| |
| // Move to next file. |
| offset += ntohl(file.len) + ntohl(file.offset); |
| if (offset % CBFS_ALIGNMENT) |
| offset += CBFS_ALIGNMENT - (offset % CBFS_ALIGNMENT); |
| } |
| media->close(media); |
| LOG("WARNING: '%s' not found.\n", name); |
| return NULL; |
| } |
| |
| void *cbfs_get_file_content(struct cbfs_media *media, const char *name, |
| int type, size_t *sz) |
| { |
| struct cbfs_file *file = cbfs_get_file(media, name); |
| |
| if (sz) |
| *sz = 0; |
| |
| if (file == NULL) { |
| ERROR("Could not find file '%s'.\n", name); |
| return NULL; |
| } |
| |
| if (ntohl(file->type) != type) { |
| ERROR("File '%s' is of type %x, but we requested %x.\n", name, |
| ntohl(file->type), type); |
| return NULL; |
| } |
| |
| void *file_content = (void *)CBFS_SUBHEADER(file); |
| |
| struct cbfs_file_attribute *attr = |
| cbfs_file_find_attr(file, CBFS_FILE_ATTR_TAG_COMPRESSION); |
| |
| size_t final_size = ntohl(file->len); |
| int compression_algo = CBFS_COMPRESS_NONE; |
| if (attr) { |
| struct cbfs_file_attr_compression *comp = |
| (struct cbfs_file_attr_compression *)attr; |
| compression_algo = ntohl(comp->compression); |
| DEBUG("File '%s' is compressed (alg=%d)\n", |
| name, compression_algo); |
| final_size = ntohl(comp->decompressed_size); |
| } |
| |
| void *dst = malloc(final_size); |
| if (dst == NULL) |
| goto err; |
| |
| if (!cbfs_decompress(compression_algo, file_content, dst, final_size)) |
| goto err; |
| |
| if (sz) |
| *sz = final_size; |
| |
| media->unmap(media, file); |
| return dst; |
| |
| err: |
| media->unmap(media, file); |
| free(dst); |
| return NULL; |
| } |
| |
| struct cbfs_file_attribute *cbfs_file_first_attr(struct cbfs_file *file) |
| { |
| /* attributes_offset should be 0 when there is no attribute, but all |
| * values that point into the cbfs_file header are invalid, too. */ |
| if (ntohl(file->attributes_offset) <= sizeof(*file)) |
| return NULL; |
| |
| /* There needs to be enough space for the file header and one |
| * attribute header for this to make sense. */ |
| if (ntohl(file->offset) <= |
| sizeof(*file) + sizeof(struct cbfs_file_attribute)) |
| return NULL; |
| |
| return (struct cbfs_file_attribute *) |
| (((uint8_t *)file) + ntohl(file->attributes_offset)); |
| } |
| |
| struct cbfs_file_attribute *cbfs_file_next_attr(struct cbfs_file *file, |
| struct cbfs_file_attribute *attr) |
| { |
| /* ex falso sequitur quodlibet */ |
| if (attr == NULL) |
| return NULL; |
| |
| /* Is there enough space for another attribute? */ |
| if ((uint8_t *)attr + ntohl(attr->len) + |
| sizeof(struct cbfs_file_attribute) >= |
| (uint8_t *)file + ntohl(file->offset)) |
| return NULL; |
| |
| struct cbfs_file_attribute *next = (struct cbfs_file_attribute *) |
| (((uint8_t *)attr) + ntohl(attr->len)); |
| /* If any, "unused" attributes must come last. */ |
| if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED) |
| return NULL; |
| if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED2) |
| return NULL; |
| |
| return next; |
| } |
| |
| struct cbfs_file_attribute *cbfs_file_find_attr(struct cbfs_file *file, |
| uint32_t tag) |
| { |
| struct cbfs_file_attribute *attr = cbfs_file_first_attr(file); |
| while (attr) { |
| if (ntohl(attr->tag) == tag) |
| break; |
| attr = cbfs_file_next_attr(file, attr); |
| } |
| return attr; |
| |
| } |
| |
| int cbfs_decompress(int algo, void *src, void *dst, int len) |
| { |
| switch (algo) { |
| case CBFS_COMPRESS_NONE: |
| memcpy(dst, src, len); |
| return len; |
| #ifdef CBFS_CORE_WITH_LZMA |
| case CBFS_COMPRESS_LZMA: |
| return ulzma(src, dst); |
| #endif |
| default: |
| ERROR("tried to decompress %d bytes with algorithm #%x," |
| "but that algorithm id is unsupported.\n", len, |
| algo); |
| return 0; |
| } |
| } |