/* * 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> #include <sysinfo.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; } static int get_cbfs_range(uint32_t *offset, uint32_t *cbfs_end, struct cbfs_media *media) { const struct cbfs_header *header; if (media == CBFS_DEFAULT_MEDIA && lib_sysinfo.cbfs_offset && lib_sysinfo.cbfs_size) { *offset = lib_sysinfo.cbfs_offset; *cbfs_end = *offset + lib_sysinfo.cbfs_size; return 0; } /* * If sysinfo doesn't have offset or size, we read them from * a master header. */ DEBUG("CBFS offset & size not found in sysinfo\n"); header = cbfs_get_header(media); if (header == CBFS_HEADER_INVALID_ADDRESS) return -1; // Logical offset (for source media) of first file. *offset = ntohl(header->offset); *cbfs_end = ntohl(header->romsize); #if IS_ENABLED(CONFIG_LP_ARCH_X86) // resolve actual length of ROM used for CBFS components // the bootblock size was not taken into account *cbfs_end -= 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)) *cbfs_end -= (CBFS_ALIGNMENT - (ntohl(header->bootblocksize) % CBFS_ALIGNMENT)); else *cbfs_end -= 1; #endif return 0; } /* public API starts here*/ struct cbfs_file *cbfs_get_file(struct cbfs_media *media, const char *name) { const char *vardata; uint32_t offset, cbfs_end, vardata_len; 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 (get_cbfs_range(&offset, &cbfs_end, media)) { ERROR("Failed to find cbfs range\n"); return NULL; } DEBUG("CBFS location: 0x%x~0x%x\n", offset, cbfs_end); DEBUG("Looking for '%s' starting from 0x%x.\n", name, offset); media->open(media); while (offset < cbfs_end && 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_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; } } 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; } }