| /* |
| * partitioned_file.c, read and write binary file "partitions" described by FMAP |
| * |
| * Copyright (C) 2015 Google, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA |
| */ |
| |
| #include "partitioned_file.h" |
| |
| #include "cbfs_sections.h" |
| |
| #include <assert.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| struct partitioned_file { |
| struct fmap *fmap; |
| struct buffer buffer; |
| FILE *stream; |
| }; |
| |
| static bool fill_ones_through(struct partitioned_file *file) |
| { |
| assert(file); |
| |
| memset(file->buffer.data, 0xff, file->buffer.size); |
| return partitioned_file_write_region(file, &file->buffer); |
| } |
| |
| static unsigned count_selected_fmap_entries(const struct fmap *fmap, |
| partitioned_file_fmap_selector_t callback, const void *arg) |
| { |
| assert(fmap); |
| assert(callback); |
| |
| unsigned count = 0; |
| for (unsigned index = 0; index < fmap->nareas; ++index) { |
| if (callback(fmap->areas + index, arg)) |
| ++count; |
| } |
| return count; |
| } |
| |
| static partitioned_file_t *reopen_flat_file(const char *filename) |
| { |
| assert(filename); |
| |
| struct partitioned_file *file = calloc(1, sizeof(*file)); |
| if (!file) { |
| ERROR("Failed to allocate partitioned file structure\n"); |
| return NULL; |
| } |
| |
| if (buffer_from_file(&file->buffer, filename)) { |
| free(file); |
| return NULL; |
| } |
| |
| file->stream = fopen(filename, "rb+"); |
| if (!file->stream) { |
| perror(filename); |
| partitioned_file_close(file); |
| return NULL; |
| } |
| |
| return file; |
| } |
| |
| partitioned_file_t *partitioned_file_create_flat(const char *filename, |
| size_t image_size) |
| { |
| assert(filename); |
| |
| struct partitioned_file *file = calloc(1, sizeof(*file)); |
| if (!file) { |
| ERROR("Failed to allocate partitioned file structure\n"); |
| return NULL; |
| } |
| |
| file->stream = fopen(filename, "wb"); |
| if (!file->stream) { |
| perror(filename); |
| free(file); |
| return NULL; |
| } |
| |
| if (buffer_create(&file->buffer, image_size, filename)) { |
| partitioned_file_close(file); |
| return NULL; |
| } |
| |
| if (!fill_ones_through(file)) { |
| partitioned_file_close(file); |
| return NULL; |
| } |
| |
| return file; |
| } |
| |
| partitioned_file_t *partitioned_file_create(const char *filename, |
| struct buffer *flashmap) |
| { |
| assert(filename); |
| assert(flashmap); |
| assert(flashmap->data); |
| |
| if (fmap_find((const uint8_t *)flashmap->data, flashmap->size) != 0) { |
| ERROR("Attempted to create a partitioned image out of something that isn't an FMAP\n"); |
| return NULL; |
| } |
| struct fmap *bootstrap_fmap = (struct fmap *)flashmap->data; |
| |
| const struct fmap_area *fmap_area = |
| fmap_find_area(bootstrap_fmap, SECTION_NAME_FMAP); |
| if (!fmap_area) { |
| ERROR("Provided FMAP missing '%s' region\n", SECTION_NAME_FMAP); |
| return NULL; |
| } |
| |
| if (count_selected_fmap_entries(bootstrap_fmap, |
| partitioned_file_fmap_select_children_of, fmap_area)) { |
| ERROR("Provided FMAP's '%s' region contains other regions\n", |
| SECTION_NAME_FMAP); |
| return NULL; |
| } |
| |
| int fmap_len = fmap_size(bootstrap_fmap); |
| if (fmap_len < 0) { |
| ERROR("Unable to determine size of provided FMAP\n"); |
| return NULL; |
| } |
| assert((size_t)fmap_len <= flashmap->size); |
| if ((uint32_t)fmap_len > fmap_area->size) { |
| ERROR("Provided FMAP's '%s' region needs to be at least %d bytes\n", |
| SECTION_NAME_FMAP, fmap_len); |
| return NULL; |
| } |
| |
| partitioned_file_t *file = partitioned_file_create_flat(filename, |
| bootstrap_fmap->size); |
| if (!file) |
| return NULL; |
| |
| struct buffer fmap_region; |
| buffer_splice(&fmap_region, &file->buffer, fmap_area->offset, fmap_area->size); |
| memcpy(fmap_region.data, bootstrap_fmap, fmap_len); |
| if (!partitioned_file_write_region(file, &fmap_region)) { |
| partitioned_file_close(file); |
| return NULL; |
| } |
| file->fmap = (struct fmap *)(file->buffer.data + fmap_area->offset); |
| |
| return file; |
| } |
| |
| partitioned_file_t *partitioned_file_reopen(const char *filename, |
| partitioned_file_flat_decider_t flat_override) |
| { |
| assert(filename); |
| |
| partitioned_file_t *file = reopen_flat_file(filename); |
| if (!file) |
| return NULL; |
| |
| if (flat_override && flat_override(&file->buffer)) { |
| INFO("Opening image as a flat file in response to explicit request\n"); |
| return file; |
| } |
| |
| long fmap_region_offset = fmap_find((const uint8_t *)file->buffer.data, |
| file->buffer.size); |
| if (fmap_region_offset < 0) { |
| INFO("Opening image as a flat file because it doesn't contain any FMAP\n"); |
| return file; |
| } |
| file->fmap = (struct fmap *)(file->buffer.data + fmap_region_offset); |
| |
| if (file->fmap->size > file->buffer.size) { |
| int fmap_region_size = fmap_size(file->fmap); |
| ERROR("FMAP records image size as %u, but file is only %zu bytes%s\n", |
| file->fmap->size, file->buffer.size, |
| fmap_region_offset == 0 && |
| (signed)file->buffer.size == fmap_region_size ? |
| " (is it really an image, or *just* an FMAP?)" : |
| " (did something truncate this file?)"); |
| partitioned_file_close(file); |
| return NULL; |
| } |
| |
| const struct fmap_area *fmap_fmap_entry = |
| fmap_find_area(file->fmap, SECTION_NAME_FMAP); |
| if ((long)fmap_fmap_entry->offset != fmap_region_offset) { |
| ERROR("FMAP's '%s' section doesn't point back to FMAP start (did something corrupt this file?)\n", |
| SECTION_NAME_FMAP); |
| partitioned_file_close(file); |
| return NULL; |
| } |
| |
| return file; |
| } |
| |
| bool partitioned_file_write_region(partitioned_file_t *file, |
| const struct buffer *buffer) |
| { |
| assert(file); |
| assert(file->stream); |
| assert(buffer); |
| assert(buffer->data); |
| |
| if (buffer->data - buffer->offset != file->buffer.data) { |
| ERROR("Attempted to write a partition buffer back to a different file than it came from\n"); |
| return false; |
| } |
| if (buffer->offset + buffer->size > file->buffer.size) { |
| ERROR("Attempted to write data off the end of image file\n"); |
| return false; |
| } |
| |
| if (fseek(file->stream, buffer->offset, SEEK_SET)) { |
| ERROR("Failed to seek within image file\n"); |
| return false; |
| } |
| if (!fwrite(buffer->data, buffer->size, 1, file->stream)) { |
| ERROR("Failed to write to image file\n"); |
| return false; |
| } |
| return true; |
| } |
| |
| bool partitioned_file_read_region(struct buffer *dest, |
| const partitioned_file_t *file, const char *region) |
| { |
| assert(dest); |
| assert(file); |
| assert(file->buffer.data); |
| assert(region); |
| |
| if (file->fmap) { |
| const struct fmap_area *area = fmap_find_area(file->fmap, |
| region); |
| if (!area) { |
| ERROR("Image is missing '%s' region\n", region); |
| return false; |
| } |
| if (area->offset + area->size > file->buffer.size) { |
| ERROR("Region '%s' runs off the end of the image file\n", |
| region); |
| return false; |
| } |
| buffer_splice(dest, &file->buffer, area->offset, area->size); |
| } else { |
| if (strcmp(region, SECTION_NAME_PRIMARY_CBFS) != 0) { |
| ERROR("This is a legacy image that contains only a CBFS\n"); |
| return false; |
| } |
| buffer_clone(dest, &file->buffer); |
| } |
| |
| return true; |
| } |
| |
| void partitioned_file_close(partitioned_file_t *file) |
| { |
| if (!file) |
| return; |
| |
| file->fmap = NULL; |
| buffer_delete(&file->buffer); |
| if (file->stream) { |
| fclose(file->stream); |
| file->stream = NULL; |
| } |
| free(file); |
| } |
| |
| bool partitioned_file_is_partitioned(const partitioned_file_t *file) |
| { |
| return partitioned_file_get_fmap(file) != NULL; |
| } |
| |
| bool partitioned_file_region_check_magic(const partitioned_file_t *file, |
| const char *region, const char *magic, size_t magic_len) |
| { |
| struct buffer area; |
| return partitioned_file_read_region(&area, file, region) && |
| buffer_check_magic(&area, magic, magic_len); |
| } |
| |
| bool partitioned_file_region_contains_nested(const partitioned_file_t *file, |
| const char *region) |
| { |
| assert(file); |
| assert(region); |
| |
| if (!file->fmap) |
| return false; |
| const struct fmap_area *area = fmap_find_area(file->fmap, region); |
| return area && partitioned_file_fmap_count(file, |
| partitioned_file_fmap_select_children_of, area); |
| } |
| |
| const struct fmap *partitioned_file_get_fmap(const partitioned_file_t *file) |
| { |
| assert(file); |
| |
| return file->fmap; |
| } |
| |
| unsigned partitioned_file_fmap_count(const partitioned_file_t *file, |
| partitioned_file_fmap_selector_t callback, const void *arg) |
| { |
| assert(file); |
| assert(callback); |
| |
| if (!file->fmap) |
| return 0; |
| return count_selected_fmap_entries(file->fmap, callback, arg); |
| } |
| |
| static bool select_all(unused const struct fmap_area *area, |
| unused const void *arg) |
| { |
| return true; |
| } |
| const partitioned_file_fmap_selector_t partitioned_file_fmap_select_all = |
| select_all; |
| |
| static bool select_children_of(const struct fmap_area *child, const void *arg) |
| { |
| assert(child); |
| assert(arg); |
| |
| const struct fmap_area *parent = (const struct fmap_area *)arg; |
| if (child == arg || (child->offset == parent->offset && |
| child->size == parent->size)) |
| return false; |
| return child->offset >= parent->offset && |
| child->offset + child->size <= parent->offset + parent->size; |
| } |
| const partitioned_file_fmap_selector_t |
| partitioned_file_fmap_select_children_of = select_children_of; |
| |
| static bool select_parents_of(const struct fmap_area *parent, const void *arg) |
| { |
| return select_children_of((const struct fmap_area *)arg, parent); |
| } |
| const partitioned_file_fmap_selector_t partitioned_file_fmap_select_parents_of = |
| select_parents_of; |
| |
| static bool open_as_flat(unused struct buffer *buffer) |
| { |
| return true; |
| } |
| const partitioned_file_flat_decider_t partitioned_file_open_as_flat = |
| open_as_flat; |