diff options
Diffstat (limited to 'drivers/md/dm-ima.c')
| -rw-r--r-- | drivers/md/dm-ima.c | 748 |
1 files changed, 748 insertions, 0 deletions
diff --git a/drivers/md/dm-ima.c b/drivers/md/dm-ima.c new file mode 100644 index 0000000000..b90f34259f --- /dev/null +++ b/drivers/md/dm-ima.c @@ -0,0 +1,748 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Microsoft Corporation + * + * Author: Tushar Sugandhi <tusharsu@linux.microsoft.com> + * + * Enables IMA measurements for DM targets + */ + +#include "dm-core.h" +#include "dm-ima.h" + +#include <linux/ima.h> +#include <linux/sched/mm.h> +#include <crypto/hash.h> +#include <linux/crypto.h> +#include <crypto/hash_info.h> + +#define DM_MSG_PREFIX "ima" + +/* + * Internal function to prefix separator characters in input buffer with escape + * character, so that they don't interfere with the construction of key-value pairs, + * and clients can split the key1=val1,key2=val2,key3=val3; pairs properly. + */ +static void fix_separator_chars(char **buf) +{ + int l = strlen(*buf); + int i, j, sp = 0; + + for (i = 0; i < l; i++) + if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',') + sp++; + + if (!sp) + return; + + for (i = l-1, j = i+sp; i >= 0; i--) { + (*buf)[j--] = (*buf)[i]; + if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',') + (*buf)[j--] = '\\'; + } +} + +/* + * Internal function to allocate memory for IMA measurements. + */ +static void *dm_ima_alloc(size_t len, gfp_t flags, bool noio) +{ + unsigned int noio_flag; + void *ptr; + + if (noio) + noio_flag = memalloc_noio_save(); + + ptr = kzalloc(len, flags); + + if (noio) + memalloc_noio_restore(noio_flag); + + return ptr; +} + +/* + * Internal function to allocate and copy name and uuid for IMA measurements. + */ +static int dm_ima_alloc_and_copy_name_uuid(struct mapped_device *md, char **dev_name, + char **dev_uuid, bool noio) +{ + int r; + *dev_name = dm_ima_alloc(DM_NAME_LEN*2, GFP_KERNEL, noio); + if (!(*dev_name)) { + r = -ENOMEM; + goto error; + } + + *dev_uuid = dm_ima_alloc(DM_UUID_LEN*2, GFP_KERNEL, noio); + if (!(*dev_uuid)) { + r = -ENOMEM; + goto error; + } + + r = dm_copy_name_and_uuid(md, *dev_name, *dev_uuid); + if (r) + goto error; + + fix_separator_chars(dev_name); + fix_separator_chars(dev_uuid); + + return 0; +error: + kfree(*dev_name); + kfree(*dev_uuid); + *dev_name = NULL; + *dev_uuid = NULL; + return r; +} + +/* + * Internal function to allocate and copy device data for IMA measurements. + */ +static int dm_ima_alloc_and_copy_device_data(struct mapped_device *md, char **device_data, + unsigned int num_targets, bool noio) +{ + char *dev_name = NULL, *dev_uuid = NULL; + int r; + + r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio); + if (r) + return r; + + *device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio); + if (!(*device_data)) { + r = -ENOMEM; + goto error; + } + + scnprintf(*device_data, DM_IMA_DEVICE_BUF_LEN, + "name=%s,uuid=%s,major=%d,minor=%d,minor_count=%d,num_targets=%u;", + dev_name, dev_uuid, md->disk->major, md->disk->first_minor, + md->disk->minors, num_targets); +error: + kfree(dev_name); + kfree(dev_uuid); + return r; +} + +/* + * Internal wrapper function to call IMA to measure DM data. + */ +static void dm_ima_measure_data(const char *event_name, const void *buf, size_t buf_len, + bool noio) +{ + unsigned int noio_flag; + + if (noio) + noio_flag = memalloc_noio_save(); + + ima_measure_critical_data(DM_NAME, event_name, buf, buf_len, + false, NULL, 0); + + if (noio) + memalloc_noio_restore(noio_flag); +} + +/* + * Internal function to allocate and copy current device capacity for IMA measurements. + */ +static int dm_ima_alloc_and_copy_capacity_str(struct mapped_device *md, char **capacity_str, + bool noio) +{ + sector_t capacity; + + capacity = get_capacity(md->disk); + + *capacity_str = dm_ima_alloc(DM_IMA_DEVICE_CAPACITY_BUF_LEN, GFP_KERNEL, noio); + if (!(*capacity_str)) + return -ENOMEM; + + scnprintf(*capacity_str, DM_IMA_DEVICE_BUF_LEN, "current_device_capacity=%llu;", + capacity); + + return 0; +} + +/* + * Initialize/reset the dm ima related data structure variables. + */ +void dm_ima_reset_data(struct mapped_device *md) +{ + memset(&(md->ima), 0, sizeof(md->ima)); + md->ima.dm_version_str_len = strlen(DM_IMA_VERSION_STR); +} + +/* + * Build up the IMA data for each target, and finally measure. + */ +void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags) +{ + size_t device_data_buf_len, target_metadata_buf_len, target_data_buf_len, l = 0; + char *target_metadata_buf = NULL, *target_data_buf = NULL, *digest_buf = NULL; + char *ima_buf = NULL, *device_data_buf = NULL; + int digest_size, last_target_measured = -1, r; + status_type_t type = STATUSTYPE_IMA; + size_t cur_total_buf_len = 0; + unsigned int num_targets, i; + SHASH_DESC_ON_STACK(shash, NULL); + struct crypto_shash *tfm = NULL; + u8 *digest = NULL; + bool noio = false; + /* + * In below hash_alg_prefix_len assignment +1 is for the additional char (':'), + * when prefixing the hash value with the hash algorithm name. e.g. sha256:<hash_value>. + */ + const size_t hash_alg_prefix_len = strlen(DM_IMA_TABLE_HASH_ALG) + 1; + char table_load_event_name[] = "dm_table_load"; + + ima_buf = dm_ima_alloc(DM_IMA_MEASUREMENT_BUF_LEN, GFP_KERNEL, noio); + if (!ima_buf) + return; + + target_metadata_buf = dm_ima_alloc(DM_IMA_TARGET_METADATA_BUF_LEN, GFP_KERNEL, noio); + if (!target_metadata_buf) + goto error; + + target_data_buf = dm_ima_alloc(DM_IMA_TARGET_DATA_BUF_LEN, GFP_KERNEL, noio); + if (!target_data_buf) + goto error; + + num_targets = table->num_targets; + + if (dm_ima_alloc_and_copy_device_data(table->md, &device_data_buf, num_targets, noio)) + goto error; + + tfm = crypto_alloc_shash(DM_IMA_TABLE_HASH_ALG, 0, 0); + if (IS_ERR(tfm)) + goto error; + + shash->tfm = tfm; + digest_size = crypto_shash_digestsize(tfm); + digest = dm_ima_alloc(digest_size, GFP_KERNEL, noio); + if (!digest) + goto error; + + r = crypto_shash_init(shash); + if (r) + goto error; + + memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len); + l += table->md->ima.dm_version_str_len; + + device_data_buf_len = strlen(device_data_buf); + memcpy(ima_buf + l, device_data_buf, device_data_buf_len); + l += device_data_buf_len; + + for (i = 0; i < num_targets; i++) { + struct dm_target *ti = dm_table_get_target(table, i); + + last_target_measured = 0; + + /* + * First retrieve the target metadata. + */ + scnprintf(target_metadata_buf, DM_IMA_TARGET_METADATA_BUF_LEN, + "target_index=%d,target_begin=%llu,target_len=%llu,", + i, ti->begin, ti->len); + target_metadata_buf_len = strlen(target_metadata_buf); + + /* + * Then retrieve the actual target data. + */ + if (ti->type->status) + ti->type->status(ti, type, status_flags, target_data_buf, + DM_IMA_TARGET_DATA_BUF_LEN); + else + target_data_buf[0] = '\0'; + + target_data_buf_len = strlen(target_data_buf); + + /* + * Check if the total data can fit into the IMA buffer. + */ + cur_total_buf_len = l + target_metadata_buf_len + target_data_buf_len; + + /* + * IMA measurements for DM targets are best-effort. + * If the total data buffered so far, including the current target, + * is too large to fit into DM_IMA_MEASUREMENT_BUF_LEN, measure what + * we have in the current buffer, and continue measuring the remaining + * targets by prefixing the device metadata again. + */ + if (unlikely(cur_total_buf_len >= DM_IMA_MEASUREMENT_BUF_LEN)) { + dm_ima_measure_data(table_load_event_name, ima_buf, l, noio); + r = crypto_shash_update(shash, (const u8 *)ima_buf, l); + if (r < 0) + goto error; + + memset(ima_buf, 0, DM_IMA_MEASUREMENT_BUF_LEN); + l = 0; + + /* + * Each new "dm_table_load" entry in IMA log should have device data + * prefix, so that multiple records from the same "dm_table_load" for + * a given device can be linked together. + */ + memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len); + l += table->md->ima.dm_version_str_len; + + memcpy(ima_buf + l, device_data_buf, device_data_buf_len); + l += device_data_buf_len; + + /* + * If this iteration of the for loop turns out to be the last target + * in the table, dm_ima_measure_data("dm_table_load", ...) doesn't need + * to be called again, just the hash needs to be finalized. + * "last_target_measured" tracks this state. + */ + last_target_measured = 1; + } + + /* + * Fill-in all the target metadata, so that multiple targets for the same + * device can be linked together. + */ + memcpy(ima_buf + l, target_metadata_buf, target_metadata_buf_len); + l += target_metadata_buf_len; + + memcpy(ima_buf + l, target_data_buf, target_data_buf_len); + l += target_data_buf_len; + } + + if (!last_target_measured) { + dm_ima_measure_data(table_load_event_name, ima_buf, l, noio); + + r = crypto_shash_update(shash, (const u8 *)ima_buf, l); + if (r < 0) + goto error; + } + + /* + * Finalize the table hash, and store it in table->md->ima.inactive_table.hash, + * so that the table data can be verified against the future device state change + * events, e.g. resume, rename, remove, table-clear etc. + */ + r = crypto_shash_final(shash, digest); + if (r < 0) + goto error; + + digest_buf = dm_ima_alloc((digest_size*2) + hash_alg_prefix_len + 1, GFP_KERNEL, noio); + + if (!digest_buf) + goto error; + + snprintf(digest_buf, hash_alg_prefix_len + 1, "%s:", DM_IMA_TABLE_HASH_ALG); + + for (i = 0; i < digest_size; i++) + snprintf((digest_buf + hash_alg_prefix_len + (i*2)), 3, "%02x", digest[i]); + + if (table->md->ima.active_table.hash != table->md->ima.inactive_table.hash) + kfree(table->md->ima.inactive_table.hash); + + table->md->ima.inactive_table.hash = digest_buf; + table->md->ima.inactive_table.hash_len = strlen(digest_buf); + table->md->ima.inactive_table.num_targets = num_targets; + + if (table->md->ima.active_table.device_metadata != + table->md->ima.inactive_table.device_metadata) + kfree(table->md->ima.inactive_table.device_metadata); + + table->md->ima.inactive_table.device_metadata = device_data_buf; + table->md->ima.inactive_table.device_metadata_len = device_data_buf_len; + + goto exit; +error: + kfree(digest_buf); + kfree(device_data_buf); +exit: + kfree(digest); + if (tfm) + crypto_free_shash(tfm); + kfree(ima_buf); + kfree(target_metadata_buf); + kfree(target_data_buf); +} + +/* + * Measure IMA data on device resume. + */ +void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap) +{ + char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL; + char active[] = "active_table_hash="; + unsigned int active_len = strlen(active), capacity_len = 0; + unsigned int l = 0; + bool noio = true; + bool nodata = true; + int r; + + device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio); + if (!device_table_data) + return; + + r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio); + if (r) + goto error; + + memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len); + l += md->ima.dm_version_str_len; + + if (swap) { + if (md->ima.active_table.hash != md->ima.inactive_table.hash) + kfree(md->ima.active_table.hash); + + md->ima.active_table.hash = NULL; + md->ima.active_table.hash_len = 0; + + if (md->ima.active_table.device_metadata != + md->ima.inactive_table.device_metadata) + kfree(md->ima.active_table.device_metadata); + + md->ima.active_table.device_metadata = NULL; + md->ima.active_table.device_metadata_len = 0; + md->ima.active_table.num_targets = 0; + + if (md->ima.inactive_table.hash) { + md->ima.active_table.hash = md->ima.inactive_table.hash; + md->ima.active_table.hash_len = md->ima.inactive_table.hash_len; + md->ima.inactive_table.hash = NULL; + md->ima.inactive_table.hash_len = 0; + } + + if (md->ima.inactive_table.device_metadata) { + md->ima.active_table.device_metadata = + md->ima.inactive_table.device_metadata; + md->ima.active_table.device_metadata_len = + md->ima.inactive_table.device_metadata_len; + md->ima.active_table.num_targets = md->ima.inactive_table.num_targets; + md->ima.inactive_table.device_metadata = NULL; + md->ima.inactive_table.device_metadata_len = 0; + md->ima.inactive_table.num_targets = 0; + } + } + + if (md->ima.active_table.device_metadata) { + memcpy(device_table_data + l, md->ima.active_table.device_metadata, + md->ima.active_table.device_metadata_len); + l += md->ima.active_table.device_metadata_len; + + nodata = false; + } + + if (md->ima.active_table.hash) { + memcpy(device_table_data + l, active, active_len); + l += active_len; + + memcpy(device_table_data + l, md->ima.active_table.hash, + md->ima.active_table.hash_len); + l += md->ima.active_table.hash_len; + + memcpy(device_table_data + l, ";", 1); + l++; + + nodata = false; + } + + if (nodata) { + r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio); + if (r) + goto error; + + scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN, + "%sname=%s,uuid=%s;device_resume=no_data;", + DM_IMA_VERSION_STR, dev_name, dev_uuid); + l = strlen(device_table_data); + + } + + capacity_len = strlen(capacity_str); + memcpy(device_table_data + l, capacity_str, capacity_len); + l += capacity_len; + + dm_ima_measure_data("dm_device_resume", device_table_data, l, noio); + + kfree(dev_name); + kfree(dev_uuid); +error: + kfree(capacity_str); + kfree(device_table_data); +} + +/* + * Measure IMA data on remove. + */ +void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all) +{ + char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL; + char active_table_str[] = "active_table_hash="; + char inactive_table_str[] = "inactive_table_hash="; + char device_active_str[] = "device_active_metadata="; + char device_inactive_str[] = "device_inactive_metadata="; + char remove_all_str[] = "remove_all="; + unsigned int active_table_len = strlen(active_table_str); + unsigned int inactive_table_len = strlen(inactive_table_str); + unsigned int device_active_len = strlen(device_active_str); + unsigned int device_inactive_len = strlen(device_inactive_str); + unsigned int remove_all_len = strlen(remove_all_str); + unsigned int capacity_len = 0; + unsigned int l = 0; + bool noio = true; + bool nodata = true; + int r; + + device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN*2, GFP_KERNEL, noio); + if (!device_table_data) + goto exit; + + r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio); + if (r) { + kfree(device_table_data); + goto exit; + } + + memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len); + l += md->ima.dm_version_str_len; + + if (md->ima.active_table.device_metadata) { + memcpy(device_table_data + l, device_active_str, device_active_len); + l += device_active_len; + + memcpy(device_table_data + l, md->ima.active_table.device_metadata, + md->ima.active_table.device_metadata_len); + l += md->ima.active_table.device_metadata_len; + + nodata = false; + } + + if (md->ima.inactive_table.device_metadata) { + memcpy(device_table_data + l, device_inactive_str, device_inactive_len); + l += device_inactive_len; + + memcpy(device_table_data + l, md->ima.inactive_table.device_metadata, + md->ima.inactive_table.device_metadata_len); + l += md->ima.inactive_table.device_metadata_len; + + nodata = false; + } + + if (md->ima.active_table.hash) { + memcpy(device_table_data + l, active_table_str, active_table_len); + l += active_table_len; + + memcpy(device_table_data + l, md->ima.active_table.hash, + md->ima.active_table.hash_len); + l += md->ima.active_table.hash_len; + + memcpy(device_table_data + l, ",", 1); + l++; + + nodata = false; + } + + if (md->ima.inactive_table.hash) { + memcpy(device_table_data + l, inactive_table_str, inactive_table_len); + l += inactive_table_len; + + memcpy(device_table_data + l, md->ima.inactive_table.hash, + md->ima.inactive_table.hash_len); + l += md->ima.inactive_table.hash_len; + + memcpy(device_table_data + l, ",", 1); + l++; + + nodata = false; + } + /* + * In case both active and inactive tables, and corresponding + * device metadata is cleared/missing - record the name and uuid + * in IMA measurements. + */ + if (nodata) { + if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio)) + goto error; + + scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN, + "%sname=%s,uuid=%s;device_remove=no_data;", + DM_IMA_VERSION_STR, dev_name, dev_uuid); + l = strlen(device_table_data); + } + + memcpy(device_table_data + l, remove_all_str, remove_all_len); + l += remove_all_len; + memcpy(device_table_data + l, remove_all ? "y;" : "n;", 2); + l += 2; + + capacity_len = strlen(capacity_str); + memcpy(device_table_data + l, capacity_str, capacity_len); + l += capacity_len; + + dm_ima_measure_data("dm_device_remove", device_table_data, l, noio); + +error: + kfree(device_table_data); + kfree(capacity_str); +exit: + kfree(md->ima.active_table.device_metadata); + + if (md->ima.active_table.device_metadata != + md->ima.inactive_table.device_metadata) + kfree(md->ima.inactive_table.device_metadata); + + kfree(md->ima.active_table.hash); + + if (md->ima.active_table.hash != md->ima.inactive_table.hash) + kfree(md->ima.inactive_table.hash); + + dm_ima_reset_data(md); + + kfree(dev_name); + kfree(dev_uuid); +} + +/* + * Measure ima data on table clear. + */ +void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map) +{ + unsigned int l = 0, capacity_len = 0; + char *device_table_data = NULL, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL; + char inactive_str[] = "inactive_table_hash="; + unsigned int inactive_len = strlen(inactive_str); + bool noio = true; + bool nodata = true; + int r; + + device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio); + if (!device_table_data) + return; + + r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio); + if (r) + goto error1; + + memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len); + l += md->ima.dm_version_str_len; + + if (md->ima.inactive_table.device_metadata_len && + md->ima.inactive_table.hash_len) { + memcpy(device_table_data + l, md->ima.inactive_table.device_metadata, + md->ima.inactive_table.device_metadata_len); + l += md->ima.inactive_table.device_metadata_len; + + memcpy(device_table_data + l, inactive_str, inactive_len); + l += inactive_len; + + memcpy(device_table_data + l, md->ima.inactive_table.hash, + md->ima.inactive_table.hash_len); + + l += md->ima.inactive_table.hash_len; + + memcpy(device_table_data + l, ";", 1); + l++; + + nodata = false; + } + + if (nodata) { + if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio)) + goto error2; + + scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN, + "%sname=%s,uuid=%s;table_clear=no_data;", + DM_IMA_VERSION_STR, dev_name, dev_uuid); + l = strlen(device_table_data); + } + + capacity_len = strlen(capacity_str); + memcpy(device_table_data + l, capacity_str, capacity_len); + l += capacity_len; + + dm_ima_measure_data("dm_table_clear", device_table_data, l, noio); + + if (new_map) { + if (md->ima.inactive_table.hash && + md->ima.inactive_table.hash != md->ima.active_table.hash) + kfree(md->ima.inactive_table.hash); + + md->ima.inactive_table.hash = NULL; + md->ima.inactive_table.hash_len = 0; + + if (md->ima.inactive_table.device_metadata && + md->ima.inactive_table.device_metadata != md->ima.active_table.device_metadata) + kfree(md->ima.inactive_table.device_metadata); + + md->ima.inactive_table.device_metadata = NULL; + md->ima.inactive_table.device_metadata_len = 0; + md->ima.inactive_table.num_targets = 0; + + if (md->ima.active_table.hash) { + md->ima.inactive_table.hash = md->ima.active_table.hash; + md->ima.inactive_table.hash_len = md->ima.active_table.hash_len; + } + + if (md->ima.active_table.device_metadata) { + md->ima.inactive_table.device_metadata = + md->ima.active_table.device_metadata; + md->ima.inactive_table.device_metadata_len = + md->ima.active_table.device_metadata_len; + md->ima.inactive_table.num_targets = + md->ima.active_table.num_targets; + } + } + + kfree(dev_name); + kfree(dev_uuid); +error2: + kfree(capacity_str); +error1: + kfree(device_table_data); +} + +/* + * Measure IMA data on device rename. + */ +void dm_ima_measure_on_device_rename(struct mapped_device *md) +{ + char *old_device_data = NULL, *new_device_data = NULL, *combined_device_data = NULL; + char *new_dev_name = NULL, *new_dev_uuid = NULL, *capacity_str = NULL; + bool noio = true; + int r; + + if (dm_ima_alloc_and_copy_device_data(md, &new_device_data, + md->ima.active_table.num_targets, noio)) + return; + + if (dm_ima_alloc_and_copy_name_uuid(md, &new_dev_name, &new_dev_uuid, noio)) + goto error; + + combined_device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN * 2, GFP_KERNEL, noio); + if (!combined_device_data) + goto error; + + r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio); + if (r) + goto error; + + old_device_data = md->ima.active_table.device_metadata; + + md->ima.active_table.device_metadata = new_device_data; + md->ima.active_table.device_metadata_len = strlen(new_device_data); + + scnprintf(combined_device_data, DM_IMA_DEVICE_BUF_LEN * 2, + "%s%snew_name=%s,new_uuid=%s;%s", DM_IMA_VERSION_STR, old_device_data, + new_dev_name, new_dev_uuid, capacity_str); + + dm_ima_measure_data("dm_device_rename", combined_device_data, strlen(combined_device_data), + noio); + + goto exit; + +error: + kfree(new_device_data); +exit: + kfree(capacity_str); + kfree(combined_device_data); + kfree(old_device_data); + kfree(new_dev_name); + kfree(new_dev_uuid); +} |