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gpt-utils.cpp
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/*
* Copyright (c) 2013,2016,2020 The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of The Linux Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 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.
*/
#define _LARGEFILE64_SOURCE /* enable lseek64() */
/******************************************************************************
* INCLUDE SECTION
******************************************************************************/
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <linux/fs.h>
#include <limits.h>
#include <dirent.h>
#include <linux/kernel.h>
#include <map>
#include <vector>
#include <string>
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#define LOG_TAG "gpt-utils"
#include <cutils/log.h>
#include <cutils/properties.h>
#include "gpt-utils.h"
#include <zlib.h>
#include <endian.h>
/******************************************************************************
* DEFINE SECTION
******************************************************************************/
#define BLK_DEV_FILE "/dev/block/mmcblk0"
/* list the names of the backed-up partitions to be swapped */
/* extension used for the backup partitions - tzbak, abootbak, etc. */
#define BAK_PTN_NAME_EXT "bak"
#define XBL_PRIMARY "/dev/block/bootdevice/by-name/xbl"
#define XBL_BACKUP "/dev/block/bootdevice/by-name/xblbak"
#define XBL_AB_PRIMARY "/dev/block/bootdevice/by-name/xbl_a"
#define XBL_AB_SECONDARY "/dev/block/bootdevice/by-name/xbl_b"
/* GPT defines */
#define MAX_LUNS 26
//This will allow us to get the root lun path from the path to the partition.
//i.e: from /dev/block/sdaXXX get /dev/block/sda. The assumption here is that
//the boot critical luns lie between sda to sdz which is acceptable because
//only user added external disks,etc would lie beyond that limit which do not
//contain partitions that interest us here.
#define PATH_TRUNCATE_LOC (sizeof("/dev/block/sda") - 1)
//From /dev/block/sda get just sda
#define LUN_NAME_START_LOC (sizeof("/dev/block/") - 1)
#define BOOT_LUN_A_ID 1
#define BOOT_LUN_B_ID 2
/******************************************************************************
* MACROS
******************************************************************************/
#define GET_4_BYTES(ptr) ((uint32_t) *((uint8_t *)(ptr)) | \
((uint32_t) *((uint8_t *)(ptr) + 1) << 8) | \
((uint32_t) *((uint8_t *)(ptr) + 2) << 16) | \
((uint32_t) *((uint8_t *)(ptr) + 3) << 24))
#define GET_8_BYTES(ptr) ((uint64_t) *((uint8_t *)(ptr)) | \
((uint64_t) *((uint8_t *)(ptr) + 1) << 8) | \
((uint64_t) *((uint8_t *)(ptr) + 2) << 16) | \
((uint64_t) *((uint8_t *)(ptr) + 3) << 24) | \
((uint64_t) *((uint8_t *)(ptr) + 4) << 32) | \
((uint64_t) *((uint8_t *)(ptr) + 5) << 40) | \
((uint64_t) *((uint8_t *)(ptr) + 6) << 48) | \
((uint64_t) *((uint8_t *)(ptr) + 7) << 56))
#define PUT_4_BYTES(ptr, y) *((uint8_t *)(ptr)) = (y) & 0xff; \
*((uint8_t *)(ptr) + 1) = ((y) >> 8) & 0xff; \
*((uint8_t *)(ptr) + 2) = ((y) >> 16) & 0xff; \
*((uint8_t *)(ptr) + 3) = ((y) >> 24) & 0xff;
/******************************************************************************
* TYPES
******************************************************************************/
using namespace std;
enum gpt_state {
GPT_OK = 0,
GPT_BAD_SIGNATURE,
GPT_BAD_CRC
};
//List of LUN's containing boot critical images.
//Required in the case of UFS devices
struct update_data {
char lun_list[MAX_LUNS][PATH_MAX];
uint32_t num_valid_entries;
};
int32_t set_boot_lun(char *sg_dev,uint8_t boot_lun_id);
/******************************************************************************
* FUNCTIONS
******************************************************************************/
/**
* ==========================================================================
*
* \brief Read/Write len bytes from/to block dev
*
* \param [in] fd block dev file descriptor (returned from open)
* \param [in] rw RW flag: 0 - read, != 0 - write
* \param [in] offset block dev offset [bytes] - RW start position
* \param [in] buf Pointer to the buffer containing the data
* \param [in] len RW size in bytes. Buf must be at least that big
*
* \return 0 on success
*
* ==========================================================================
*/
static int blk_rw(int fd, int rw, int64_t offset, uint8_t *buf, unsigned len)
{
int r;
if (lseek64(fd, offset, SEEK_SET) < 0) {
fprintf(stderr, "block dev lseek64 %" PRIi64 " failed: %s\n", offset,
strerror(errno));
return -1;
}
if (rw)
r = write(fd, buf, len);
else
r = read(fd, buf, len);
if (r < 0) {
fprintf(stderr, "block dev %s failed: %s\n", rw ? "write" : "read",
strerror(errno));
} else {
if (rw) {
r = fsync(fd);
if (r < 0)
fprintf(stderr, "fsync failed: %s\n", strerror(errno));
} else {
r = 0;
}
}
return r;
}
/**
* ==========================================================================
*
* \brief Search within GPT for partition entry with the given name
* or it's backup twin (name-bak).
*
* \param [in] ptn_name Partition name to seek
* \param [in] pentries_start Partition entries array start pointer
* \param [in] pentries_end Partition entries array end pointer
* \param [in] pentry_size Single partition entry size [bytes]
*
* \return First partition entry pointer that matches the name or NULL
*
* ==========================================================================
*/
static uint8_t *gpt_pentry_seek(const char *ptn_name,
const uint8_t *pentries_start,
const uint8_t *pentries_end,
uint32_t pentry_size)
{
char *pentry_name;
unsigned len = strlen(ptn_name);
unsigned i;
char name8[MAX_GPT_NAME_SIZE] = {0}; // initialize with null
for (pentry_name = (char *) (pentries_start + PARTITION_NAME_OFFSET);
pentry_name < (char *) pentries_end;
pentry_name += pentry_size) {
/* Partition names in GPT are UTF-16 - ignoring UTF-16 2nd byte */
for (i = 0; i < sizeof(name8) / 2; i++)
name8[i] = pentry_name[i * 2];
name8[i] = '\0';
if (!strncmp(ptn_name, name8, len)) {
if (name8[len] == 0 || !strcmp(&name8[len], BAK_PTN_NAME_EXT))
return (uint8_t *) (pentry_name - PARTITION_NAME_OFFSET);
}
}
return NULL;
}
/**
* ==========================================================================
*
* \brief Swaps boot chain in GPT partition entries array
*
* \param [in] pentries_start Partition entries array start
* \param [in] pentries_end Partition entries array end
* \param [in] pentry_size Single partition entry size
*
* \return 0 on success, 1 if no backup partitions found
*
* ==========================================================================
*/
static int gpt_boot_chain_swap(const uint8_t *pentries_start,
const uint8_t *pentries_end,
uint32_t pentry_size)
{
const char ptn_swap_list[][MAX_GPT_NAME_SIZE] = { PTN_SWAP_LIST };
int backup_not_found = 1;
unsigned i;
for (i = 0; i < ARRAY_SIZE(ptn_swap_list); i++) {
uint8_t *ptn_entry;
uint8_t *ptn_bak_entry;
uint8_t ptn_swap[PTN_ENTRY_SIZE];
//Skip the xbl partition on UFS devices. That is handled
//seperately.
if (gpt_utils_is_ufs_device() && !strncmp(ptn_swap_list[i],
PTN_XBL,
strlen(PTN_XBL)))
continue;
ptn_entry = gpt_pentry_seek(ptn_swap_list[i], pentries_start,
pentries_end, pentry_size);
if (ptn_entry == NULL)
continue;
ptn_bak_entry = gpt_pentry_seek(ptn_swap_list[i],
ptn_entry + pentry_size, pentries_end, pentry_size);
if (ptn_bak_entry == NULL) {
fprintf(stderr, "'%s' partition not backup - skip safe update\n",
ptn_swap_list[i]);
continue;
}
/* swap primary <-> backup partition entries */
memcpy(ptn_swap, ptn_entry, PTN_ENTRY_SIZE);
memcpy(ptn_entry, ptn_bak_entry, PTN_ENTRY_SIZE);
memcpy(ptn_bak_entry, ptn_swap, PTN_ENTRY_SIZE);
backup_not_found = 0;
}
return backup_not_found;
}
/**
* ==========================================================================
*
* \brief Sets secondary GPT boot chain
*
* \param [in] fd block dev file descriptor
* \param [in] boot Boot chain to switch to
*
* \return 0 on success
*
* ==========================================================================
*/
static int gpt2_set_boot_chain(int fd, enum boot_chain boot)
{
int64_t gpt2_header_offset;
uint64_t pentries_start_offset;
uint32_t gpt_header_size;
uint32_t pentry_size;
uint32_t pentries_array_size;
uint8_t *gpt_header = NULL;
uint8_t *pentries = NULL;
uint32_t crc;
uint32_t crc_zero;
uint32_t blk_size = 0;
int r;
crc_zero = crc32(0L, Z_NULL, 0);
if (ioctl(fd, BLKSSZGET, &blk_size) != 0) {
fprintf(stderr, "Failed to get GPT device block size: %s\n",
strerror(errno));
r = -1;
goto EXIT;
}
gpt_header = (uint8_t*)malloc(blk_size);
if (!gpt_header) {
fprintf(stderr, "Failed to allocate memory to hold GPT block\n");
r = -1;
goto EXIT;
}
gpt2_header_offset = lseek64(fd, 0, SEEK_END) - blk_size;
if (gpt2_header_offset < 0) {
fprintf(stderr, "Getting secondary GPT header offset failed: %s\n",
strerror(errno));
r = -1;
goto EXIT;
}
/* Read primary GPT header from block dev */
r = blk_rw(fd, 0, blk_size, gpt_header, blk_size);
if (r) {
fprintf(stderr, "Failed to read primary GPT header from blk dev\n");
goto EXIT;
}
pentries_start_offset =
GET_8_BYTES(gpt_header + PENTRIES_OFFSET) * blk_size;
pentry_size = GET_4_BYTES(gpt_header + PENTRY_SIZE_OFFSET);
pentries_array_size =
GET_4_BYTES(gpt_header + PARTITION_COUNT_OFFSET) * pentry_size;
pentries = (uint8_t *) calloc(1, pentries_array_size);
if (pentries == NULL) {
fprintf(stderr,
"Failed to alloc memory for GPT partition entries array\n");
r = -1;
goto EXIT;
}
/* Read primary GPT partititon entries array from block dev */
r = blk_rw(fd, 0, pentries_start_offset, pentries, pentries_array_size);
if (r)
goto EXIT;
crc = crc32(crc_zero, pentries, pentries_array_size);
if (GET_4_BYTES(gpt_header + PARTITION_CRC_OFFSET) != crc) {
fprintf(stderr, "Primary GPT partition entries array CRC invalid\n");
r = -1;
goto EXIT;
}
/* Read secondary GPT header from block dev */
r = blk_rw(fd, 0, gpt2_header_offset, gpt_header, blk_size);
if (r)
goto EXIT;
gpt_header_size = GET_4_BYTES(gpt_header + HEADER_SIZE_OFFSET);
pentries_start_offset =
GET_8_BYTES(gpt_header + PENTRIES_OFFSET) * blk_size;
if (boot == BACKUP_BOOT) {
r = gpt_boot_chain_swap(pentries, pentries + pentries_array_size,
pentry_size);
if (r)
goto EXIT;
}
crc = crc32(crc_zero, pentries, pentries_array_size);
PUT_4_BYTES(gpt_header + PARTITION_CRC_OFFSET, crc);
/* header CRC is calculated with this field cleared */
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, 0);
crc = crc32(crc_zero, gpt_header, gpt_header_size);
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, crc);
/* Write the modified GPT header back to block dev */
r = blk_rw(fd, 1, gpt2_header_offset, gpt_header, blk_size);
if (!r)
/* Write the modified GPT partititon entries array back to block dev */
r = blk_rw(fd, 1, pentries_start_offset, pentries,
pentries_array_size);
EXIT:
if(gpt_header)
free(gpt_header);
if (pentries)
free(pentries);
return r;
}
/**
* ==========================================================================
*
* \brief Checks GPT state (header signature and CRC)
*
* \param [in] fd block dev file descriptor
* \param [in] gpt GPT header to be checked
* \param [out] state GPT header state
*
* \return 0 on success
*
* ==========================================================================
*/
static int gpt_get_state(int fd, enum gpt_instance gpt, enum gpt_state *state)
{
int64_t gpt_header_offset;
uint32_t gpt_header_size;
uint8_t *gpt_header = NULL;
uint32_t crc;
uint32_t crc_zero;
uint32_t blk_size = 0;
*state = GPT_OK;
crc_zero = crc32(0L, Z_NULL, 0);
if (ioctl(fd, BLKSSZGET, &blk_size) != 0) {
fprintf(stderr, "Failed to get GPT device block size: %s\n",
strerror(errno));
goto error;
}
gpt_header = (uint8_t*)malloc(blk_size);
if (!gpt_header) {
fprintf(stderr, "gpt_get_state:Failed to alloc memory for header\n");
goto error;
}
if (gpt == PRIMARY_GPT)
gpt_header_offset = blk_size;
else {
gpt_header_offset = lseek64(fd, 0, SEEK_END) - blk_size;
if (gpt_header_offset < 0) {
fprintf(stderr, "gpt_get_state:Seek to end of GPT part fail\n");
goto error;
}
}
if (blk_rw(fd, 0, gpt_header_offset, gpt_header, blk_size)) {
fprintf(stderr, "gpt_get_state: blk_rw failed\n");
goto error;
}
if (memcmp(gpt_header, GPT_SIGNATURE, sizeof(GPT_SIGNATURE)))
*state = GPT_BAD_SIGNATURE;
gpt_header_size = GET_4_BYTES(gpt_header + HEADER_SIZE_OFFSET);
crc = GET_4_BYTES(gpt_header + HEADER_CRC_OFFSET);
/* header CRC is calculated with this field cleared */
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, 0);
if (crc32(crc_zero, gpt_header, gpt_header_size) != crc)
*state = GPT_BAD_CRC;
free(gpt_header);
return 0;
error:
if (gpt_header)
free(gpt_header);
return -1;
}
/**
* ==========================================================================
*
* \brief Sets GPT header state (used to corrupt and fix GPT signature)
*
* \param [in] fd block dev file descriptor
* \param [in] gpt GPT header to be checked
* \param [in] state GPT header state to set (GPT_OK or GPT_BAD_SIGNATURE)
*
* \return 0 on success
*
* ==========================================================================
*/
static int gpt_set_state(int fd, enum gpt_instance gpt, enum gpt_state state)
{
int64_t gpt_header_offset;
uint32_t gpt_header_size;
uint8_t *gpt_header = NULL;
uint32_t crc;
uint32_t crc_zero;
uint32_t blk_size = 0;
crc_zero = crc32(0L, Z_NULL, 0);
if (ioctl(fd, BLKSSZGET, &blk_size) != 0) {
fprintf(stderr, "Failed to get GPT device block size: %s\n",
strerror(errno));
goto error;
}
gpt_header = (uint8_t*)malloc(blk_size);
if (!gpt_header) {
fprintf(stderr, "Failed to alloc memory for gpt header\n");
goto error;
}
if (gpt == PRIMARY_GPT)
gpt_header_offset = blk_size;
else {
gpt_header_offset = lseek64(fd, 0, SEEK_END) - blk_size;
if (gpt_header_offset < 0) {
fprintf(stderr, "Failed to seek to end of GPT device\n");
goto error;
}
}
if (blk_rw(fd, 0, gpt_header_offset, gpt_header, blk_size)) {
fprintf(stderr, "Failed to r/w gpt header\n");
goto error;
}
if (state == GPT_OK)
memcpy(gpt_header, GPT_SIGNATURE, sizeof(GPT_SIGNATURE));
else if (state == GPT_BAD_SIGNATURE)
*gpt_header = 0;
else {
fprintf(stderr, "gpt_set_state: Invalid state\n");
goto error;
}
gpt_header_size = GET_4_BYTES(gpt_header + HEADER_SIZE_OFFSET);
/* header CRC is calculated with this field cleared */
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, 0);
crc = crc32(crc_zero, gpt_header, gpt_header_size);
PUT_4_BYTES(gpt_header + HEADER_CRC_OFFSET, crc);
if (blk_rw(fd, 1, gpt_header_offset, gpt_header, blk_size)) {
fprintf(stderr, "gpt_set_state: blk write failed\n");
goto error;
}
return 0;
error:
if(gpt_header)
free(gpt_header);
return -1;
}
int get_scsi_node_from_bootdevice(const char *bootdev_path,
char *sg_node_path,
size_t buf_size)
{
char sg_dir_path[PATH_MAX] = {0};
char real_path[PATH_MAX] = {0};
DIR *scsi_dir = NULL;
struct dirent *de;
int node_found = 0;
if (!bootdev_path || !sg_node_path) {
fprintf(stderr, "%s : invalid argument\n",
__func__);
goto error;
}
if (readlink(bootdev_path, real_path, sizeof(real_path) - 1) < 0) {
fprintf(stderr, "failed to resolve link for %s(%s)\n",
bootdev_path,
strerror(errno));
goto error;
}
if(strlen(real_path) < PATH_TRUNCATE_LOC + 1){
fprintf(stderr, "Unrecognized path :%s:\n",
real_path);
goto error;
}
//For the safe side in case there are additional partitions on
//the XBL lun we truncate the name.
real_path[PATH_TRUNCATE_LOC] = '\0';
if(strlen(real_path) < LUN_NAME_START_LOC + 1){
fprintf(stderr, "Unrecognized truncated path :%s:\n",
real_path);
goto error;
}
//This will give us /dev/block/sdb/device/scsi_generic
//which contains a file sgY whose name gives us the path
//to /dev/sgY which we return
snprintf(sg_dir_path, sizeof(sg_dir_path) - 1,
"/sys/block/%s/device/scsi_generic",
&real_path[LUN_NAME_START_LOC]);
scsi_dir = opendir(sg_dir_path);
if (!scsi_dir) {
fprintf(stderr, "%s : Failed to open %s(%s)\n",
__func__,
sg_dir_path,
strerror(errno));
goto error;
}
while((de = readdir(scsi_dir))) {
if (de->d_name[0] == '.')
continue;
else if (!strncmp(de->d_name, "sg", 2)) {
snprintf(sg_node_path,
buf_size -1,
"/dev/%s",
de->d_name);
fprintf(stderr, "%s:scsi generic node is :%s:\n",
__func__,
sg_node_path);
node_found = 1;
break;
}
}
if(!node_found) {
fprintf(stderr,"%s: Unable to locate scsi generic node\n",
__func__);
goto error;
}
closedir(scsi_dir);
return 0;
error:
if (scsi_dir)
closedir(scsi_dir);
return -1;
}
//Swtich betwieen using either the primary or the backup
//boot LUN for boot. This is required since UFS boot partitions
//cannot have a backup GPT which is what we use for failsafe
//updates of the other 'critical' partitions. This function will
//not be invoked for emmc targets and on UFS targets is only required
//to be invoked for XBL.
//
//The algorithm to do this is as follows:
//- Find the real block device(eg: /dev/block/sdb) that corresponds
// to the /dev/block/bootdevice/by-name/xbl(bak) symlink
//
//- Once we have the block device 'node' name(sdb in the above example)
// use this node to to locate the scsi generic device that represents
// it by checking the file /sys/block/sdb/device/scsi_generic/sgY
//
//- Once we locate sgY we call the query ioctl on /dev/sgy to switch
//the boot lun to either LUNA or LUNB
int gpt_utils_set_xbl_boot_partition(enum boot_chain chain)
{
struct stat st;
///sys/block/sdX/device/scsi_generic/
char sg_dev_node[PATH_MAX] = {0};
uint8_t boot_lun_id = 0;
const char *boot_dev = NULL;
if (chain == BACKUP_BOOT) {
boot_lun_id = BOOT_LUN_B_ID;
if (!stat(XBL_BACKUP, &st))
boot_dev = XBL_BACKUP;
else if (!stat(XBL_AB_SECONDARY, &st))
boot_dev = XBL_AB_SECONDARY;
else {
fprintf(stderr, "%s: Failed to locate secondary xbl\n",
__func__);
goto error;
}
} else if (chain == NORMAL_BOOT) {
boot_lun_id = BOOT_LUN_A_ID;
if (!stat(XBL_PRIMARY, &st))
boot_dev = XBL_PRIMARY;
else if (!stat(XBL_AB_PRIMARY, &st))
boot_dev = XBL_AB_PRIMARY;
else {
fprintf(stderr, "%s: Failed to locate primary xbl\n",
__func__);
goto error;
}
} else {
fprintf(stderr, "%s: Invalid boot chain id\n", __func__);
goto error;
}
//We need either both xbl and xblbak or both xbl_a and xbl_b to exist at
//the same time. If not the current configuration is invalid.
if((stat(XBL_PRIMARY, &st) ||
stat(XBL_BACKUP, &st)) &&
(stat(XBL_AB_PRIMARY, &st) ||
stat(XBL_AB_SECONDARY, &st))) {
fprintf(stderr, "%s:primary/secondary XBL prt not found(%s)\n",
__func__,
strerror(errno));
goto error;
}
fprintf(stderr, "%s: setting %s lun as boot lun\n",
__func__,
boot_dev);
if (get_scsi_node_from_bootdevice(boot_dev,
sg_dev_node,
sizeof(sg_dev_node))) {
fprintf(stderr, "%s: Failed to get scsi node path for xblbak\n",
__func__);
goto error;
}
/* set boot lun using /dev/sg or /dev/ufs-bsg* */
if (set_boot_lun(sg_dev_node, boot_lun_id)) {
fprintf(stderr, "%s: Failed to set xblbak as boot partition\n",
__func__);
goto error;
}
return 0;
error:
return -1;
}
int gpt_utils_is_ufs_device()
{
char bootdevice[PROPERTY_VALUE_MAX] = {0};
property_get("ro.boot.bootdevice", bootdevice, "N/A");
if (strlen(bootdevice) < strlen(".ufshc") + 1)
return 0;
return (!strncmp(&bootdevice[strlen(bootdevice) - strlen(".ufshc")],
".ufshc",
sizeof(".ufshc")));
}
//dev_path is the path to the block device that contains the GPT image that
//needs to be updated. This would be the device which holds one or more critical
//boot partitions and their backups. In the case of EMMC this function would
//be invoked only once on /dev/block/mmcblk1 since it holds the GPT image
//containing all the partitions For UFS devices it could potentially be
//invoked multiple times, once for each LUN containing critical image(s) and
//their backups
int prepare_partitions(enum boot_update_stage stage, const char *dev_path)
{
int r = 0;
int fd = -1;
int is_ufs = gpt_utils_is_ufs_device();
enum gpt_state gpt_prim, gpt_second;
enum boot_update_stage internal_stage;
struct stat xbl_partition_stat;
if (!dev_path) {
fprintf(stderr, "%s: Invalid dev_path\n",
__func__);
r = -1;
goto EXIT;
}
fd = open(dev_path, O_RDWR);
if (fd < 0) {
fprintf(stderr, "%s: Opening '%s' failed: %s\n",
__func__,
BLK_DEV_FILE,
strerror(errno));
r = -1;
goto EXIT;
}
r = gpt_get_state(fd, PRIMARY_GPT, &gpt_prim) ||
gpt_get_state(fd, SECONDARY_GPT, &gpt_second);
if (r) {
fprintf(stderr, "%s: Getting GPT headers state failed\n",
__func__);
goto EXIT;
}
/* These 2 combinations are unexpected and unacceptable */
if (gpt_prim == GPT_BAD_CRC || gpt_second == GPT_BAD_CRC) {
fprintf(stderr, "%s: GPT headers CRC corruption detected, aborting\n",
__func__);
r = -1;
goto EXIT;
}
if (gpt_prim == GPT_BAD_SIGNATURE && gpt_second == GPT_BAD_SIGNATURE) {
fprintf(stderr, "%s: Both GPT headers corrupted, aborting\n",
__func__);
r = -1;
goto EXIT;
}
/* Check internal update stage according GPT headers' state */
if (gpt_prim == GPT_OK && gpt_second == GPT_OK)
internal_stage = UPDATE_MAIN;
else if (gpt_prim == GPT_BAD_SIGNATURE)
internal_stage = UPDATE_BACKUP;
else if (gpt_second == GPT_BAD_SIGNATURE)
internal_stage = UPDATE_FINALIZE;
else {
fprintf(stderr, "%s: Abnormal GPTs state: primary (%d), secondary (%d), "
"aborting\n", __func__, gpt_prim, gpt_second);
r = -1;
goto EXIT;
}
/* Stage already set - ready for update, exitting */
if ((int) stage == (int) internal_stage - 1)
goto EXIT;
/* Unexpected stage given */
if (stage != internal_stage) {
r = -1;
goto EXIT;
}
switch (stage) {
case UPDATE_MAIN:
if (is_ufs) {
if(stat(XBL_PRIMARY, &xbl_partition_stat)||
stat(XBL_BACKUP, &xbl_partition_stat)){
//Non fatal error. Just means this target does not
//use XBL but relies on sbl whose update is handled
//by the normal methods.
fprintf(stderr, "%s: xbl part not found(%s).Assuming sbl in use\n",
__func__,
strerror(errno));
} else {
//Switch the boot lun so that backup boot LUN is used
r = gpt_utils_set_xbl_boot_partition(BACKUP_BOOT);
if(r){
fprintf(stderr, "%s: Failed to set xbl backup partition as boot\n",
__func__);
goto EXIT;
}
}
}
//Fix up the backup GPT table so that it actually points to
//the backup copy of the boot critical images
fprintf(stderr, "%s: Preparing for primary partition update\n",
__func__);
r = gpt2_set_boot_chain(fd, BACKUP_BOOT);
if (r) {
if (r < 0)
fprintf(stderr,
"%s: Setting secondary GPT to backup boot failed\n",
__func__);
/* No backup partitions - do not corrupt GPT, do not flag error */
else
r = 0;
goto EXIT;
}
//corrupt the primary GPT so that the backup(which now points to
//the backup boot partitions is used)
r = gpt_set_state(fd, PRIMARY_GPT, GPT_BAD_SIGNATURE);
if (r) {
fprintf(stderr, "%s: Corrupting primary GPT header failed\n",
__func__);
goto EXIT;
}
break;
case UPDATE_BACKUP:
if (is_ufs) {
if(stat(XBL_PRIMARY, &xbl_partition_stat)||
stat(XBL_BACKUP, &xbl_partition_stat)){
//Non fatal error. Just means this target does not
//use XBL but relies on sbl whose update is handled
//by the normal methods.
fprintf(stderr, "%s: xbl part not found(%s).Assuming sbl in use\n",
__func__,
strerror(errno));
} else {
//Switch the boot lun so that backup boot LUN is used
r = gpt_utils_set_xbl_boot_partition(NORMAL_BOOT);
if(r) {
fprintf(stderr, "%s: Failed to set xbl backup partition as boot\n",
__func__);
goto EXIT;
}
}
}
//Fix the primary GPT header so that is used
fprintf(stderr, "%s: Preparing for backup partition update\n",
__func__);
r = gpt_set_state(fd, PRIMARY_GPT, GPT_OK);
if (r) {
fprintf(stderr, "%s: Fixing primary GPT header failed\n",
__func__);
goto EXIT;
}
//Corrupt the scondary GPT header
r = gpt_set_state(fd, SECONDARY_GPT, GPT_BAD_SIGNATURE);
if (r) {
fprintf(stderr, "%s: Corrupting secondary GPT header failed\n",
__func__);
goto EXIT;
}
break;
case UPDATE_FINALIZE:
//Undo the changes we had made in the UPDATE_MAIN stage so that the
//primary/backup GPT headers once again point to the same set of
//partitions
fprintf(stderr, "%s: Finalizing partitions\n",
__func__);
r = gpt2_set_boot_chain(fd, NORMAL_BOOT);
if (r < 0) {
fprintf(stderr, "%s: Setting secondary GPT to normal boot failed\n",
__func__);
goto EXIT;
}
r = gpt_set_state(fd, SECONDARY_GPT, GPT_OK);
if (r) {
fprintf(stderr, "%s: Fixing secondary GPT header failed\n",
__func__);
goto EXIT;
}
break;
default:;
}
EXIT:
if (fd >= 0) {
fsync(fd);
close(fd);
}
return r;
}
int add_lun_to_update_list(char *lun_path, struct update_data *dat)
{
uint32_t i = 0;
struct stat st;
if (!lun_path || !dat){
fprintf(stderr, "%s: Invalid data",
__func__);
return -1;
}
if (stat(lun_path, &st)) {
fprintf(stderr, "%s: Unable to access %s. Skipping adding to list",
__func__,
lun_path);
return -1;
}
if (dat->num_valid_entries == 0) {
fprintf(stderr, "%s: Copying %s into lun_list[%d]\n",
__func__,
lun_path,
i);
strlcpy(dat->lun_list[0], lun_path,
PATH_MAX * sizeof(char));
dat->num_valid_entries = 1;
} else {
for (i = 0; (i < dat->num_valid_entries) &&
(dat->num_valid_entries < MAX_LUNS - 1); i++) {
//Check if the current LUN is not already part
//of the lun list
if (!strncmp(lun_path,dat->lun_list[i],
strlen(dat->lun_list[i]))) {
//LUN already in list..Return
return 0;
}
}
fprintf(stderr, "%s: Copying %s into lun_list[%d]\n",
__func__,
lun_path,
dat->num_valid_entries);
//Add LUN path lun list
strlcpy(dat->lun_list[dat->num_valid_entries], lun_path,
PATH_MAX * sizeof(char));
dat->num_valid_entries++;
}
return 0;
}
int prepare_boot_update(enum boot_update_stage stage)
{
int is_ufs = gpt_utils_is_ufs_device();
struct stat ufs_dir_stat;
struct update_data data;
int rcode = 0;
uint32_t i = 0;
int is_error = 0;
const char ptn_swap_list[][MAX_GPT_NAME_SIZE] = { PTN_SWAP_LIST };
//Holds /dev/block/bootdevice/by-name/*bak entry
char buf[PATH_MAX] = {0};
//Holds the resolved path of the symlink stored in buf
char real_path[PATH_MAX] = {0};
if (!is_ufs) {
//emmc device. Just pass in path to mmcblk0
return prepare_partitions(stage, BLK_DEV_FILE);
} else {
//Now we need to find the list of LUNs over
//which the boot critical images are spread
//and set them up for failsafe updates.To do
//this we find out where the symlinks for the
//each of the paths under
///dev/block/bootdevice/by-name/PTN_SWAP_LIST
//actually point to.
fprintf(stderr, "%s: Running on a UFS device\n",
__func__);
memset(&data, '\0', sizeof(struct update_data));
for (i=0; i < ARRAY_SIZE(ptn_swap_list); i++) {
//XBL on UFS does not follow the convention
//of being loaded based on well known GUID'S.
//We take care of switching the UFS boot LUN
//explicitly later on.
if (!strncmp(ptn_swap_list[i],
PTN_XBL,
strlen(PTN_XBL)))
continue;
snprintf(buf, sizeof(buf),
"%s/%sbak",
BOOT_DEV_DIR,
ptn_swap_list[i]);
if (stat(buf, &ufs_dir_stat)) {
continue;
}
if (readlink(buf, real_path, sizeof(real_path) - 1) < 0)
{
fprintf(stderr, "%s: readlink error. Skipping %s",
__func__,
strerror(errno));
} else {
if(strlen(real_path) < PATH_TRUNCATE_LOC + 1){
fprintf(stderr, "Unknown path.Skipping :%s:\n",
real_path);
} else {