/* * Copyright (c) 2016, The Linux Foundation. All rights reserved. * Copyright (C) 2021-2022 Caleb Connolly * * 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, either version 3 of the License, or * (at your option) any later version. * * 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, see . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "utils.h" #include "gpt-utils.h" #include "ufs-bsg.h" #include "bootctrl.h" #define BOOTDEV_DIR "/dev/disk/by-partlabel" #define BOOT_IMG_PTN_NAME "boot_" #define LUN_NAME_END_LOC 14 #define BOOT_SLOT_PROP "slot_suffix" #define MAX_CMDLINE_SIZE 4096 #define SLOT_ACTIVE 1 #define SLOT_INACTIVE 2 #define UPDATE_SLOT(pentry, guid, slot_state) \ ({ \ memcpy(pentry, guid, TYPE_GUID_SIZE); \ if (slot_state == SLOT_ACTIVE) \ *(pentry + AB_FLAG_OFFSET) = AB_SLOT_ACTIVE_VAL; \ else if (slot_state == SLOT_INACTIVE) \ *(pentry + AB_FLAG_OFFSET) = \ (*(pentry + AB_FLAG_OFFSET) & \ ~AB_PARTITION_ATTR_SLOT_ACTIVE); \ }) using namespace std; const char *slot_suffix_arr[] = { AB_SLOT_A_SUFFIX, AB_SLOT_B_SUFFIX, NULL }; enum part_attr_type { ATTR_SLOT_ACTIVE = 0, ATTR_BOOT_SUCCESSFUL, ATTR_UNBOOTABLE, ATTR_BOOTABLE, }; void get_kernel_cmdline_arg(const char *arg, char *buf, const char *def) { int fd; char pcmd[MAX_CMDLINE_SIZE]; char *val, *found, *ptr = buf; fd = open("/proc/cmdline", O_RDONLY); int rc = read(fd, pcmd, MAX_CMDLINE_SIZE); if (rc < 0) { fprintf(stderr, "Couldn't open /proc/cmdline: %d (%s)\n", rc, strerror(errno)); goto error; } close(fd); found = strstr(pcmd, arg); if (!found || !(val = strstr(found, "="))) { fprintf(stderr, "Couldn't find cmdline arg: '%s'\n", arg); goto error; } val++; // no this doesn't handle quotes lol while (*val != ' ') { *ptr++ = *val++; } return; error: strcpy(buf, def); } //Get the value of one of the attribute fields for a partition. static int get_partition_attribute(char *partname, enum part_attr_type part_attr) { struct gpt_disk *disk = NULL; uint8_t *pentry = NULL; int retval = -1; uint8_t *attr = NULL; if (!partname) goto error; disk = gpt_disk_alloc(); if (!disk) { fprintf(stderr, "%s: Failed to alloc disk struct\n", __func__); goto error; } if (gpt_disk_get_disk_info(partname, disk)) { fprintf(stderr, "%s: Failed to get disk info\n", __func__); goto error; } pentry = gpt_disk_get_pentry(disk, partname, PRIMARY_GPT); if (!pentry) { fprintf(stderr, "%s: pentry does not exist in disk struct\n", __func__); goto error; } attr = pentry + AB_FLAG_OFFSET; LOGD("get_partition_attribute() partname = %s, attr = 0x%x\n", partname, *attr); if (part_attr == ATTR_SLOT_ACTIVE) { retval = !!(*attr & AB_PARTITION_ATTR_SLOT_ACTIVE); LOGD("ATTR_SLOT_ACTIVE, retval = %d\n", retval); } else if (part_attr == ATTR_BOOT_SUCCESSFUL) { retval = !!(*attr & AB_PARTITION_ATTR_BOOT_SUCCESSFUL); LOGD("AB_PARTITION_ATTR_BOOT_SUCCESSFUL, retval = %d\n", retval); } else if (part_attr == ATTR_UNBOOTABLE) { retval = !!(*attr & AB_PARTITION_ATTR_UNBOOTABLE); LOGD("AB_PARTITION_ATTR_UNBOOTABLE, retval = %d\n", retval); } else { retval = -1; } gpt_disk_free(disk); return retval; error: if (disk) gpt_disk_free(disk); return retval; } //Set a particular attribute for all the partitions in a //slot static int update_slot_attribute(const char *slot, enum part_attr_type ab_attr) { unsigned int i = 0; char buf[PATH_MAX]; struct stat st; struct gpt_disk *disk = NULL; uint8_t *pentry = NULL; uint8_t *pentry_bak = NULL; int rc = -1; uint8_t *attr = NULL; uint8_t *attr_bak = NULL; char partName[MAX_GPT_NAME_SIZE + 1] = { 0 }; const char ptn_list[][MAX_GPT_NAME_SIZE - 1] = { AB_PTN_LIST }; int slot_name_valid = 0; if (!slot) { fprintf(stderr, "%s: Invalid argument\n", __func__); goto error; } for (i = 0; slot_suffix_arr[i] != NULL; i++) { if (!strncmp(slot, slot_suffix_arr[i], strlen(slot_suffix_arr[i]))) slot_name_valid = 1; } if (!slot_name_valid) { fprintf(stderr, "%s: Invalid slot name\n", __func__); goto error; } for (i = 0; i < ARRAY_SIZE(ptn_list); i++) { memset(buf, '\0', sizeof(buf)); //Check if A/B versions of this ptn exist snprintf(buf, sizeof(buf) - 1, "%s/%s%s", BOOT_DEV_DIR, ptn_list[i], AB_SLOT_A_SUFFIX); if (stat(buf, &st) < 0) { //partition does not have _a version continue; } memset(buf, '\0', sizeof(buf)); snprintf(buf, sizeof(buf) - 1, "%s/%s%s", BOOT_DEV_DIR, ptn_list[i], AB_SLOT_B_SUFFIX); if (stat(buf, &st) < 0) { //partition does not have _b version continue; } memset(partName, '\0', sizeof(partName)); snprintf(partName, sizeof(partName) - 1, "%s%s", ptn_list[i], slot); disk = gpt_disk_alloc(); if (!disk) { fprintf(stderr, "%s: Failed to alloc disk struct\n", __func__); goto error; } rc = gpt_disk_get_disk_info(partName, disk); if (rc != 0) { fprintf(stderr, "%s: Failed to get disk info for %s\n", __func__, partName); goto error; } pentry = gpt_disk_get_pentry(disk, partName, PRIMARY_GPT); pentry_bak = gpt_disk_get_pentry(disk, partName, SECONDARY_GPT); if (!pentry || !pentry_bak) { fprintf(stderr, "%s: Failed to get pentry/pentry_bak for %s\n", __func__, partName); goto error; } attr = pentry + AB_FLAG_OFFSET; LOGD("%s: got pentry for part '%s': 0x%lx (at flags: 0x%x)\n", __func__, partName, *(uint64_t *)pentry, *attr); attr_bak = pentry_bak + AB_FLAG_OFFSET; switch (ab_attr) { case ATTR_BOOT_SUCCESSFUL: *attr = (*attr) | AB_PARTITION_ATTR_BOOT_SUCCESSFUL; *attr_bak = (*attr_bak) | AB_PARTITION_ATTR_BOOT_SUCCESSFUL; break; case ATTR_UNBOOTABLE: *attr = (*attr) | AB_PARTITION_ATTR_UNBOOTABLE; *attr_bak = (*attr_bak) | AB_PARTITION_ATTR_UNBOOTABLE; break; case ATTR_BOOTABLE: *attr = (*attr) ^ AB_PARTITION_ATTR_UNBOOTABLE; *attr_bak = (*attr_bak) ^ AB_PARTITION_ATTR_UNBOOTABLE; break; case ATTR_SLOT_ACTIVE: *attr = (*attr) | AB_PARTITION_ATTR_SLOT_ACTIVE; *attr_bak = (*attr) | AB_PARTITION_ATTR_SLOT_ACTIVE; break; default: fprintf(stderr, "%s: Unrecognized attr\n", __func__); goto error; } if (gpt_disk_update_crc(disk)) { fprintf(stderr, "%s: Failed to update crc for %s\n", __func__, partName); goto error; } if (gpt_disk_commit(disk)) { fprintf(stderr, "%s: Failed to write back entry for %s\n", __func__, partName); goto error; } gpt_disk_free(disk); disk = NULL; } return 0; error: if (disk) gpt_disk_free(disk); return -1; } unsigned get_number_slots() { struct dirent *de = NULL; DIR *dir_bootdev = NULL; unsigned slot_count = 0; dir_bootdev = opendir(BOOTDEV_DIR); if (!dir_bootdev) { fprintf(stderr, "%s: Failed to open bootdev dir (%s)\n", __func__, strerror(errno)); goto error; } while ((de = readdir(dir_bootdev))) { if (de->d_name[0] == '.') continue; static_assert(AB_SLOT_A_SUFFIX[0] == '_', "Breaking change to slot A suffix"); static_assert(AB_SLOT_B_SUFFIX[0] == '_', "Breaking change to slot B suffix"); if (!strncmp(de->d_name, BOOT_IMG_PTN_NAME, strlen(BOOT_IMG_PTN_NAME)) && !!strncmp(de->d_name, "boot_aging\n", strlen("boot_aging"))) { slot_count++; } } closedir(dir_bootdev); return slot_count; error: if (dir_bootdev) closedir(dir_bootdev); return 0; } static unsigned int get_current_slot() { uint32_t num_slots = 0; char bootSlotProp[MAX_CMDLINE_SIZE] = { '\0' }; unsigned i = 0; num_slots = get_number_slots(); if (num_slots <= 1) { //Slot 0 is the only slot around. return 0; } get_kernel_cmdline_arg(BOOT_SLOT_PROP, bootSlotProp, "_a"); if (!strncmp(bootSlotProp, "N/A\n", strlen("N/A"))) { fprintf(stderr, "%s: Unable to read boot slot property\n", __func__); goto error; } //Iterate through a list of partitons named as boot+suffix //and see which one is currently active. for (i = 0; slot_suffix_arr[i] != NULL; i++) { if (!strncmp(bootSlotProp, slot_suffix_arr[i], strlen(slot_suffix_arr[i]))) { //printf("%s current_slot = %d\n", __func__, i); return i; } } error: //The HAL spec requires that we return a number between //0 to num_slots - 1. Since something went wrong here we //are just going to return the default slot. return 0; } static int boot_control_check_slot_sanity(unsigned slot) { uint32_t num_slots = get_number_slots(); if ((num_slots < 1) || (slot > num_slots - 1)) { fprintf(stderr, "Invalid slot number"); return -1; } return 0; } int get_boot_attr(unsigned slot, enum part_attr_type attr) { char bootPartition[MAX_GPT_NAME_SIZE + 1] = { 0 }; if (boot_control_check_slot_sanity(slot) != 0) { fprintf(stderr, "%s: Argument check failed\n", __func__); return -1; } snprintf(bootPartition, sizeof(bootPartition) - 1, "boot%s", slot_suffix_arr[slot]); return get_partition_attribute(bootPartition, attr); } int is_slot_bootable(unsigned slot) { int attr = 0; attr = get_boot_attr(slot, ATTR_UNBOOTABLE); if (attr >= 0) return !attr; return -1; } int mark_boot_successful(unsigned slot) { int successful = get_boot_attr(slot, ATTR_BOOT_SUCCESSFUL); if (!is_slot_bootable(slot)) { printf("SLOT %s: was marked unbootable, fixing this" " (I hope you know what you're doing...)\n", slot_suffix_arr[slot]); update_slot_attribute(slot_suffix_arr[slot], ATTR_BOOTABLE); } if (successful) { fprintf(stderr, "SLOT %s: already marked successful\n", slot_suffix_arr[slot]); return 0; } if (update_slot_attribute(slot_suffix_arr[slot], ATTR_BOOT_SUCCESSFUL)) { goto error; } return 0; error: fprintf(stderr, "SLOT %s: Failed to mark boot successful\n", slot_suffix_arr[slot]); return -1; } const char *get_suffix(unsigned slot) { if (boot_control_check_slot_sanity(slot) != 0) return NULL; else return slot_suffix_arr[slot]; } //Return a gpt disk structure representing the disk that holds //partition. static struct gpt_disk *boot_ctl_get_disk_info(char *partition) { struct gpt_disk *disk = NULL; if (!partition) return NULL; disk = gpt_disk_alloc(); if (!disk) { fprintf(stderr, "%s: Failed to alloc disk\n", __func__); goto error; } if (gpt_disk_get_disk_info(partition, disk)) { fprintf(stderr, "failed to get disk info for %s\n", partition); goto error; } return disk; error: if (disk) gpt_disk_free(disk); return NULL; } //The argument here is a vector of partition names(including the slot suffix) //that lie on a single disk static int boot_ctl_set_active_slot_for_partitions(vector part_list, unsigned slot) { char buf[PATH_MAX] = { 0 }; struct gpt_disk *disk = NULL; char slotA[MAX_GPT_NAME_SIZE + 1] = { 0 }; char slotB[MAX_GPT_NAME_SIZE + 1] = { 0 }; char active_guid[TYPE_GUID_SIZE + 1] = { 0 }; char inactive_guid[TYPE_GUID_SIZE + 1] = { 0 }; int rc; //Pointer to the partition entry of current 'A' partition uint8_t *pentryA = NULL; uint8_t *pentryA_bak = NULL; //Pointer to partition entry of current 'B' partition uint8_t *pentryB = NULL; uint8_t *pentryB_bak = NULL; struct stat st; vector::iterator partition_iterator; LOGD("Marking slot %s as active:\n", slot_suffix_arr[slot]); for (partition_iterator = part_list.begin(); partition_iterator != part_list.end(); partition_iterator++) { //Chop off the slot suffix from the partition name to //make the string easier to work with. string prefix = *partition_iterator; LOGD("Part: %s\n", prefix.c_str()); if (prefix.size() < (strlen(AB_SLOT_A_SUFFIX) + 1)) { fprintf(stderr, "Invalid partition name: %s\n", prefix.c_str()); goto error; } prefix.resize(prefix.size() - strlen(AB_SLOT_A_SUFFIX)); //Check if A/B versions of this ptn exist snprintf(buf, sizeof(buf) - 1, "%s/%s%s", BOOT_DEV_DIR, prefix.c_str(), AB_SLOT_A_SUFFIX); LOGD("\t_a Path: '%s'\n", buf); rc = stat(buf, &st); if (rc < 0) { fprintf(stderr, "Failed to stat() path: %d: %s\n", rc, strerror(errno)); continue; } memset(buf, '\0', sizeof(buf)); snprintf(buf, sizeof(buf) - 1, "%s/%s%s", BOOT_DEV_DIR, prefix.c_str(), AB_SLOT_B_SUFFIX); LOGD("\t_b Path: '%s'\n", buf); rc = stat(buf, &st); if (rc < 0) { fprintf(stderr, "Failed to stat() path: %d: %s\n", rc, strerror(errno)); continue; } memset(slotA, 0, sizeof(slotA)); memset(slotB, 0, sizeof(slotA)); snprintf(slotA, sizeof(slotA) - 1, "%s%s", prefix.c_str(), AB_SLOT_A_SUFFIX); snprintf(slotB, sizeof(slotB) - 1, "%s%s", prefix.c_str(), AB_SLOT_B_SUFFIX); //Get the disk containing the partitions that were passed in. //All partitions passed in must lie on the same disk. if (!disk) { disk = boot_ctl_get_disk_info(slotA); if (!disk) goto error; } //Get partition entry for slot A & B from the primary //and backup tables. pentryA = gpt_disk_get_pentry(disk, slotA, PRIMARY_GPT); pentryA_bak = gpt_disk_get_pentry(disk, slotA, SECONDARY_GPT); pentryB = gpt_disk_get_pentry(disk, slotB, PRIMARY_GPT); pentryB_bak = gpt_disk_get_pentry(disk, slotB, SECONDARY_GPT); if (!pentryA || !pentryA_bak || !pentryB || !pentryB_bak) { //None of these should be NULL since we have already //checked for A & B versions earlier. fprintf(stderr, "Slot pentries for %s not found.\n", prefix.c_str()); goto error; } LOGD("\tAB attr (A): 0x%x (backup: 0x%x)\n", *(uint16_t *)(pentryA + AB_FLAG_OFFSET), *(uint16_t *)(pentryA_bak + AB_FLAG_OFFSET)); LOGD("\tAB attr (B): 0x%x (backup: 0x%x)\n", *(uint16_t *)(pentryB + AB_FLAG_OFFSET), *(uint16_t *)(pentryB_bak + AB_FLAG_OFFSET)); memset(active_guid, '\0', sizeof(active_guid)); memset(inactive_guid, '\0', sizeof(inactive_guid)); if (get_partition_attribute(slotA, ATTR_SLOT_ACTIVE) == 1) { //A is the current active slot memcpy((void *)active_guid, (const void *)pentryA, TYPE_GUID_SIZE); memcpy((void *)inactive_guid, (const void *)pentryB, TYPE_GUID_SIZE); } else if (get_partition_attribute(slotB, ATTR_SLOT_ACTIVE) == 1) { //B is the current active slot memcpy((void *)active_guid, (const void *)pentryB, TYPE_GUID_SIZE); memcpy((void *)inactive_guid, (const void *)pentryA, TYPE_GUID_SIZE); } else { fprintf(stderr, "Both A & B are inactive..Aborting"); goto error; } // printf("\tActive GUID: %s\n", active_guid); // printf("\tInactive GUID: %s\n", active_guid); if (!strncmp(slot_suffix_arr[slot], AB_SLOT_A_SUFFIX, strlen(AB_SLOT_A_SUFFIX))) { //Mark A as active in primary table UPDATE_SLOT(pentryA, active_guid, SLOT_ACTIVE); //Mark A as active in backup table UPDATE_SLOT(pentryA_bak, active_guid, SLOT_ACTIVE); //Mark B as inactive in primary table UPDATE_SLOT(pentryB, inactive_guid, SLOT_INACTIVE); //Mark B as inactive in backup table UPDATE_SLOT(pentryB_bak, inactive_guid, SLOT_INACTIVE); } else if (!strncmp(slot_suffix_arr[slot], AB_SLOT_B_SUFFIX, strlen(AB_SLOT_B_SUFFIX))) { //Mark B as active in primary table UPDATE_SLOT(pentryB, active_guid, SLOT_ACTIVE); //Mark B as active in backup table UPDATE_SLOT(pentryB_bak, active_guid, SLOT_ACTIVE); //Mark A as inavtive in primary table UPDATE_SLOT(pentryA, inactive_guid, SLOT_INACTIVE); //Mark A as inactive in backup table UPDATE_SLOT(pentryA_bak, inactive_guid, SLOT_INACTIVE); } else { //Something has gone terribly terribly wrong fprintf(stderr, "%s: Unknown slot suffix!\n", __func__); goto error; } if (gpt_disk_update_crc(disk) != 0) { fprintf(stderr, "%s: Failed to update gpt_disk crc\n", __func__); goto error; } } //write updated content to disk if (disk) { if (gpt_disk_commit(disk)) { fprintf(stderr, "Failed to commit disk entry"); goto error; } gpt_disk_free(disk); } return 0; error: if (disk) gpt_disk_free(disk); return -1; } unsigned get_active_boot_slot() { uint32_t num_slots = get_number_slots(); if (num_slots <= 1) { //Slot 0 is the only slot around. return 0; } for (uint32_t i = 0; i < num_slots; i++) { if (get_boot_attr(i, ATTR_SLOT_ACTIVE)) return i; } fprintf(stderr, "%s: Failed to find the active boot slot\n", __func__); return 0; } int set_active_boot_slot(unsigned slot) { map > ptn_map; vector ptn_vec; const char ptn_list[][MAX_GPT_NAME_SIZE] = { AB_PTN_LIST }; uint32_t i; int rc = -1; map >::iterator map_iter; bool ismmc; if (boot_control_check_slot_sanity(slot)) { fprintf(stderr, "%s: Bad arguments\n", __func__); goto error; } ismmc = gpt_utils_is_partition_backed_by_emmc(PTN_XBL AB_SLOT_A_SUFFIX); if (!ismmc && ufs_bsg_dev_open() < 0) { goto error; } //The partition list just contains prefixes(without the _a/_b) of the //partitions that support A/B. In order to get the layout we need the //actual names. To do this we append the slot suffix to every member //in the list. for (i = 0; i < ARRAY_SIZE(ptn_list); i++) { //XBL is handled differrently for ufs devices so ignore it if (!ismmc && !strncmp(ptn_list[i], PTN_XBL, strlen(PTN_XBL))) continue; //The partition list will be the list of _a partitions string cur_ptn = ptn_list[i]; cur_ptn.append(AB_SLOT_A_SUFFIX); ptn_vec.push_back(cur_ptn); } //The partition map gives us info in the following format: // [path_to_block_device_1]--> // [path_to_block_device_2]--> // ... // ... // eg: // [/dev/block/sdb]---> if (gpt_utils_get_partition_map(ptn_vec, ptn_map)) { fprintf(stderr, "%s: Failed to get partition map\n", __func__); goto error; } for (map_iter = ptn_map.begin(); map_iter != ptn_map.end(); map_iter++) { if (map_iter->second.size() < 1) continue; if (boot_ctl_set_active_slot_for_partitions(map_iter->second, slot)) { fprintf(stderr, "%s: Failed to set active slot for partitions \n", __func__); ; goto error; } } // EMMC doesn't need attributes to be set. if (ismmc) return 0; if (!strncmp(slot_suffix_arr[slot], AB_SLOT_A_SUFFIX, strlen(AB_SLOT_A_SUFFIX))) { //Set xbl_a as the boot lun rc = gpt_utils_set_xbl_boot_partition(NORMAL_BOOT); } else if (!strncmp(slot_suffix_arr[slot], AB_SLOT_B_SUFFIX, strlen(AB_SLOT_B_SUFFIX))) { //Set xbl_b as the boot lun rc = gpt_utils_set_xbl_boot_partition(BACKUP_BOOT); } else { //Something has gone terribly terribly wrong fprintf(stderr, "%s: Unknown slot suffix!\n", __func__); goto error; } if (rc) { fprintf(stderr, "%s: Failed to switch xbl boot partition\n", __func__); goto error; } return 0; error: return -1; } int set_slot_as_unbootable(unsigned slot) { if (boot_control_check_slot_sanity(slot) != 0) { fprintf(stderr, "%s: Argument check failed\n", __func__); goto error; } if (update_slot_attribute(slot_suffix_arr[slot], ATTR_UNBOOTABLE)) { goto error; } return 0; error: fprintf(stderr, "%s: Failed to mark slot unbootable\n", __func__); return -1; } int is_slot_marked_successful(unsigned slot) { int attr = 0; char bootPartition[MAX_GPT_NAME_SIZE + 1] = { 0 }; if (boot_control_check_slot_sanity(slot) != 0) { fprintf(stderr, "%s: Argument check failed\n", __func__); goto error; } snprintf(bootPartition, sizeof(bootPartition) - 1, "boot%s", slot_suffix_arr[slot]); attr = get_partition_attribute(bootPartition, ATTR_BOOT_SUCCESSFUL); LOGD("%s: slot = %d, attr = 0x%x\n", __func__, slot, attr); if (attr >= 0) return attr; error: return -1; } const struct boot_control_module bootctl = { .getCurrentSlot = get_current_slot, .markBootSuccessful = mark_boot_successful, .setActiveBootSlot = set_active_boot_slot, .setSlotAsUnbootable = set_slot_as_unbootable, .isSlotBootable = is_slot_bootable, .getSuffix = get_suffix, .isSlotMarkedSuccessful = is_slot_marked_successful, .getActiveBootSlot = get_active_boot_slot, };