/*
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* Copyright (C) 2015 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <linux/fs.h>
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#include <sys/ioctl.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <arpa/inet.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <bootloader_message/bootloader_message.h>
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#include <cutils/properties.h>
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#include "bootinfo.h"
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int boot_info_open_partition(const char *name, uint64_t *out_size, int flags)
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{
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const char* dev = "/dev/block/by-name/";
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char *path;
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int fd;
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size_t trimmed_len, name_len;
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trimmed_len = strlen(dev);
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name_len = strlen(name);
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path = static_cast<char *>(calloc(trimmed_len + name_len + 1, 1));
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strncpy(path, dev, trimmed_len);
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strncpy(path + trimmed_len, name, name_len);
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fd = open(path, flags);
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free(path);
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// If we successfully opened the device, get size if requested.
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if (fd != -1 && out_size != NULL) {
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if (ioctl(fd, BLKGETSIZE64, out_size) != 0) {
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close(fd);
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return -1;
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}
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}
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return fd;
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}
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// As per struct bootloader_message_ab which is defined in
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// bootable/recovery/bootloader.h we can use the 32 bytes in the
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// bootctrl_suffix field provided that they start with the active slot
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// suffix terminated by NUL. It just so happens that BrilloBootInfo is
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// laid out this way.
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#define BOOTINFO_OFFSET offsetof(struct bootloader_message_ab, slot_suffix)
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bool boot_info_load(BrilloBootInfo *out_info)
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{
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int fd;
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memset(out_info, '\0', sizeof(BrilloBootInfo));
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fd = boot_info_open_partition("misc", NULL, O_RDONLY);
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if (fd == -1)
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return false;
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if (lseek(fd, BOOTINFO_OFFSET, SEEK_SET) != BOOTINFO_OFFSET) {
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close(fd);
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return false;
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}
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ssize_t num_read;
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do {
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num_read = read(fd, (void*) out_info, sizeof(BrilloBootInfo));
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} while (num_read == -1 && errno == EINTR);
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close(fd);
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if (num_read != sizeof(BrilloBootInfo))
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return false;
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return true;
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}
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bool boot_info_save(BrilloBootInfo *info)
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{
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int fd;
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fd = boot_info_open_partition("misc", NULL, O_RDWR);
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if (fd == -1)
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return false;
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if (lseek(fd, BOOTINFO_OFFSET, SEEK_SET) != BOOTINFO_OFFSET) {
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close(fd);
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return false;
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}
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ssize_t num_written;
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do {
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num_written = write(fd, (void*) info, sizeof(BrilloBootInfo));
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} while (num_written == -1 && errno == EINTR);
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close(fd);
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if (num_written != sizeof(BrilloBootInfo))
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return false;
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return true;
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}
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bool boot_info_validate(BrilloBootInfo* info)
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{
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if (info->magic[0] != 'B' ||
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info->magic[1] != 'C' ||
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info->magic[2] != 'c')
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return false;
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if (info->active_slot >= 2)
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return false;
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return true;
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}
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void boot_info_reset(BrilloBootInfo* info)
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{
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memset(info, '\0', sizeof(BrilloBootInfo));
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info->magic[0] = 'B';
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info->magic[1] = 'C';
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info->magic[2] = 'c';
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}
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