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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 | // SPDX-License-Identifier: GPL-2.0 /* * Common methods for use with dell-wmi-sysman * * Copyright (c) 2020 Dell Inc. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/fs.h> #include <linux/dmi.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/wmi.h> #include "dell-wmi-sysman.h" #include "../../firmware_attributes_class.h" #define MAX_TYPES 4 #include <linux/nls.h> struct wmi_sysman_priv wmi_priv = { .mutex = __MUTEX_INITIALIZER(wmi_priv.mutex), }; /* reset bios to defaults */ static const char * const reset_types[] = {"builtinsafe", "lastknowngood", "factory", "custom"}; static int reset_option = -1; static struct class *fw_attr_class; /** * populate_string_buffer() - populates a string buffer * @buffer: the start of the destination buffer * @buffer_len: length of the destination buffer * @str: the string to insert into buffer */ ssize_t populate_string_buffer(char *buffer, size_t buffer_len, const char *str) { u16 *length = (u16 *)buffer; u16 *target = length + 1; int ret; ret = utf8s_to_utf16s(str, strlen(str), UTF16_HOST_ENDIAN, target, buffer_len - sizeof(u16)); if (ret < 0) { dev_err(wmi_priv.class_dev, "UTF16 conversion failed\n"); return ret; } if ((ret * sizeof(u16)) > U16_MAX) { dev_err(wmi_priv.class_dev, "Error string too long\n"); return -ERANGE; } *length = ret * sizeof(u16); return sizeof(u16) + *length; } /** * calculate_string_buffer() - determines size of string buffer for use with BIOS communication * @str: the string to calculate based upon * */ size_t calculate_string_buffer(const char *str) { /* u16 length field + one UTF16 char for each input char */ return sizeof(u16) + strlen(str) * sizeof(u16); } /** * calculate_security_buffer() - determines size of security buffer for authentication scheme * @authentication: the authentication content * * Currently only supported type is Admin password */ size_t calculate_security_buffer(char *authentication) { if (strlen(authentication) > 0) { return (sizeof(u32) * 2) + strlen(authentication) + strlen(authentication) % 2; } return sizeof(u32) * 2; } /** * populate_security_buffer() - builds a security buffer for authentication scheme * @buffer: the buffer to populate * @authentication: the authentication content * * Currently only supported type is PLAIN TEXT */ void populate_security_buffer(char *buffer, char *authentication) { char *auth = buffer + sizeof(u32) * 2; u32 *sectype = (u32 *) buffer; u32 *seclen = sectype + 1; *sectype = strlen(authentication) > 0 ? 1 : 0; *seclen = strlen(authentication); /* plain text */ if (strlen(authentication) > 0) memcpy(auth, authentication, *seclen); } /** * map_wmi_error() - map errors from WMI methods to kernel error codes * @error_code: integer error code returned from Dell's firmware */ int map_wmi_error(int error_code) { switch (error_code) { case 0: /* success */ return 0; case 1: /* failed */ return -EIO; case 2: /* invalid parameter */ return -EINVAL; case 3: /* access denied */ return -EACCES; case 4: /* not supported */ return -EOPNOTSUPP; case 5: /* memory error */ return -ENOMEM; case 6: /* protocol error */ return -EPROTO; } /* unspecified error */ return -EIO; } /** * reset_bios_show() - sysfs implementaton for read reset_bios * @kobj: Kernel object for this attribute * @attr: Kernel object attribute * @buf: The buffer to display to userspace */ static ssize_t reset_bios_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { char *start = buf; int i; for (i = 0; i < MAX_TYPES; i++) { if (i == reset_option) buf += sprintf(buf, "[%s] ", reset_types[i]); else buf += sprintf(buf, "%s ", reset_types[i]); } buf += sprintf(buf, "\n"); return buf-start; } /** * reset_bios_store() - sysfs implementaton for write reset_bios * @kobj: Kernel object for this attribute * @attr: Kernel object attribute * @buf: The buffer from userspace * @count: the size of the buffer from userspace */ static ssize_t reset_bios_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { int type = sysfs_match_string(reset_types, buf); int ret; if (type < 0) return type; ret = set_bios_defaults(type); pr_debug("reset all attributes request type %d: %d\n", type, ret); if (!ret) { reset_option = type; ret = count; } return ret; } /** * pending_reboot_show() - sysfs implementaton for read pending_reboot * @kobj: Kernel object for this attribute * @attr: Kernel object attribute * @buf: The buffer to display to userspace * * Stores default value as 0 * When current_value is changed this attribute is set to 1 to notify reboot may be required */ static ssize_t pending_reboot_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", wmi_priv.pending_changes); } static struct kobj_attribute reset_bios = __ATTR_RW(reset_bios); static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot); /** * create_attributes_level_sysfs_files() - Creates reset_bios and * pending_reboot attributes */ static int create_attributes_level_sysfs_files(void) { int ret; ret = sysfs_create_file(&wmi_priv.main_dir_kset->kobj, &reset_bios.attr); if (ret) return ret; ret = sysfs_create_file(&wmi_priv.main_dir_kset->kobj, &pending_reboot.attr); if (ret) return ret; return 0; } static ssize_t wmi_sysman_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { struct kobj_attribute *kattr; ssize_t ret = -EIO; kattr = container_of(attr, struct kobj_attribute, attr); if (kattr->show) ret = kattr->show(kobj, kattr, buf); return ret; } static ssize_t wmi_sysman_attr_store(struct kobject *kobj, struct attribute *attr, const char *buf, size_t count) { struct kobj_attribute *kattr; ssize_t ret = -EIO; kattr = container_of(attr, struct kobj_attribute, attr); if (kattr->store) ret = kattr->store(kobj, kattr, buf, count); return ret; } static const struct sysfs_ops wmi_sysman_kobj_sysfs_ops = { .show = wmi_sysman_attr_show, .store = wmi_sysman_attr_store, }; static void attr_name_release(struct kobject *kobj) { kfree(kobj); } static struct kobj_type attr_name_ktype = { .release = attr_name_release, .sysfs_ops = &wmi_sysman_kobj_sysfs_ops, }; /** * strlcpy_attr - Copy a length-limited, NULL-terminated string with bound checks * @dest: Where to copy the string to * @src: Where to copy the string from */ void strlcpy_attr(char *dest, char *src) { size_t len = strlen(src) + 1; if (len > 1 && len <= MAX_BUFF) strscpy(dest, src, len); /*len can be zero because any property not-applicable to attribute can * be empty so check only for too long buffers and log error */ if (len > MAX_BUFF) pr_err("Source string returned from BIOS is out of bound!\n"); } /** * get_wmiobj_pointer() - Get Content of WMI block for particular instance * @instance_id: WMI instance ID * @guid_string: WMI GUID (in str form) * * Fetches the content for WMI block (instance_id) under GUID (guid_string) * Caller must kfree the return */ union acpi_object *get_wmiobj_pointer(int instance_id, const char *guid_string) { struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL }; acpi_status status; status = wmi_query_block(guid_string, instance_id, &out); return ACPI_SUCCESS(status) ? (union acpi_object *)out.pointer : NULL; } /** * get_instance_count() - Compute total number of instances under guid_string * @guid_string: WMI GUID (in string form) */ int get_instance_count(const char *guid_string) { union acpi_object *wmi_obj = NULL; int i = 0; do { kfree(wmi_obj); wmi_obj = get_wmiobj_pointer(i, guid_string); i++; } while (wmi_obj); return (i-1); } /** * alloc_attributes_data() - Allocate attributes data for a particular type * @attr_type: Attribute type to allocate */ static int alloc_attributes_data(int attr_type) { int retval = 0; switch (attr_type) { case ENUM: retval = alloc_enum_data(); break; case INT: retval = alloc_int_data(); break; case STR: retval = alloc_str_data(); break; case PO: retval = alloc_po_data(); break; default: break; } return retval; } /** * destroy_attribute_objs() - Free a kset of kobjects * @kset: The kset to destroy * * Fress kobjects created for each attribute_name under attribute type kset */ static void destroy_attribute_objs(struct kset *kset) { struct kobject *pos, *next; list_for_each_entry_safe(pos, next, &kset->list, entry) { kobject_put(pos); } } /** * release_attributes_data() - Clean-up all sysfs directories and files created */ static void release_attributes_data(void) { mutex_lock(&wmi_priv.mutex); exit_enum_attributes(); exit_int_attributes(); exit_str_attributes(); exit_po_attributes(); if (wmi_priv.authentication_dir_kset) { destroy_attribute_objs(wmi_priv.authentication_dir_kset); kset_unregister(wmi_priv.authentication_dir_kset); wmi_priv.authentication_dir_kset = NULL; } if (wmi_priv.main_dir_kset) { sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &reset_bios.attr); sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &pending_reboot.attr); destroy_attribute_objs(wmi_priv.main_dir_kset); kset_unregister(wmi_priv.main_dir_kset); wmi_priv.main_dir_kset = NULL; } mutex_unlock(&wmi_priv.mutex); } /** * init_bios_attributes() - Initialize all attributes for a type * @attr_type: The attribute type to initialize * @guid: The WMI GUID associated with this type to initialize * * Initialiaze all 4 types of attributes enumeration, integer, string and password object. * Populates each attrbute typ's respective properties under sysfs files */ static int init_bios_attributes(int attr_type, const char *guid) { struct kobject *attr_name_kobj; //individual attribute names union acpi_object *obj = NULL; union acpi_object *elements; struct kset *tmp_set; int min_elements; /* instance_id needs to be reset for each type GUID * also, instance IDs are unique within GUID but not across */ int instance_id = 0; int retval = 0; retval = alloc_attributes_data(attr_type); if (retval) return retval; switch (attr_type) { case ENUM: min_elements = 8; break; case INT: min_elements = 9; break; case STR: min_elements = 8; break; case PO: min_elements = 4; break; default: pr_err("Error: Unknown attr_type: %d\n", attr_type); return -EINVAL; } /* need to use specific instance_id and guid combination to get right data */ obj = get_wmiobj_pointer(instance_id, guid); if (!obj) return -ENODEV; mutex_lock(&wmi_priv.mutex); while (obj) { if (obj->type != ACPI_TYPE_PACKAGE) { pr_err("Error: Expected ACPI-package type, got: %d\n", obj->type); retval = -EIO; goto err_attr_init; } if (obj->package.count < min_elements) { pr_err("Error: ACPI-package does not have enough elements: %d < %d\n", obj->package.count, min_elements); goto nextobj; } elements = obj->package.elements; /* sanity checking */ if (elements[ATTR_NAME].type != ACPI_TYPE_STRING) { pr_debug("incorrect element type\n"); goto nextobj; } if (strlen(elements[ATTR_NAME].string.pointer) == 0) { pr_debug("empty attribute found\n"); goto nextobj; } if (attr_type == PO) tmp_set = wmi_priv.authentication_dir_kset; else tmp_set = wmi_priv.main_dir_kset; if (kset_find_obj(tmp_set, elements[ATTR_NAME].string.pointer)) { pr_debug("duplicate attribute name found - %s\n", elements[ATTR_NAME].string.pointer); goto nextobj; } /* build attribute */ attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL); if (!attr_name_kobj) { retval = -ENOMEM; goto err_attr_init; } attr_name_kobj->kset = tmp_set; retval = kobject_init_and_add(attr_name_kobj, &attr_name_ktype, NULL, "%s", elements[ATTR_NAME].string.pointer); if (retval) { kobject_put(attr_name_kobj); goto err_attr_init; } /* enumerate all of this attribute */ switch (attr_type) { case ENUM: retval = populate_enum_data(elements, instance_id, attr_name_kobj, obj->package.count); break; case INT: retval = populate_int_data(elements, instance_id, attr_name_kobj); break; case STR: retval = populate_str_data(elements, instance_id, attr_name_kobj); break; case PO: retval = populate_po_data(elements, instance_id, attr_name_kobj); break; default: break; } if (retval) { pr_debug("failed to populate %s\n", elements[ATTR_NAME].string.pointer); goto err_attr_init; } nextobj: kfree(obj); instance_id++; obj = get_wmiobj_pointer(instance_id, guid); } mutex_unlock(&wmi_priv.mutex); return 0; err_attr_init: mutex_unlock(&wmi_priv.mutex); kfree(obj); return retval; } static int __init sysman_init(void) { int ret = 0; if (!dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "Dell System", NULL) && !dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "www.dell.com", NULL)) { pr_err("Unable to run on non-Dell system\n"); return -ENODEV; } ret = init_bios_attr_set_interface(); if (ret) return ret; ret = init_bios_attr_pass_interface(); if (ret) goto err_exit_bios_attr_set_interface; if (!wmi_priv.bios_attr_wdev || !wmi_priv.password_attr_wdev) { pr_debug("failed to find set or pass interface\n"); ret = -ENODEV; goto err_exit_bios_attr_pass_interface; } ret = fw_attributes_class_get(&fw_attr_class); if (ret) goto err_exit_bios_attr_pass_interface; wmi_priv.class_dev = device_create(fw_attr_class, NULL, MKDEV(0, 0), NULL, "%s", DRIVER_NAME); if (IS_ERR(wmi_priv.class_dev)) { ret = PTR_ERR(wmi_priv.class_dev); goto err_unregister_class; } wmi_priv.main_dir_kset = kset_create_and_add("attributes", NULL, &wmi_priv.class_dev->kobj); if (!wmi_priv.main_dir_kset) { ret = -ENOMEM; goto err_destroy_classdev; } wmi_priv.authentication_dir_kset = kset_create_and_add("authentication", NULL, &wmi_priv.class_dev->kobj); if (!wmi_priv.authentication_dir_kset) { ret = -ENOMEM; goto err_release_attributes_data; } ret = create_attributes_level_sysfs_files(); if (ret) { pr_debug("could not create reset BIOS attribute\n"); goto err_release_attributes_data; } ret = init_bios_attributes(ENUM, DELL_WMI_BIOS_ENUMERATION_ATTRIBUTE_GUID); if (ret) { pr_debug("failed to populate enumeration type attributes\n"); goto err_release_attributes_data; } ret = init_bios_attributes(INT, DELL_WMI_BIOS_INTEGER_ATTRIBUTE_GUID); if (ret) { pr_debug("failed to populate integer type attributes\n"); goto err_release_attributes_data; } ret = init_bios_attributes(STR, DELL_WMI_BIOS_STRING_ATTRIBUTE_GUID); if (ret) { pr_debug("failed to populate string type attributes\n"); goto err_release_attributes_data; } ret = init_bios_attributes(PO, DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID); if (ret) { pr_debug("failed to populate pass object type attributes\n"); goto err_release_attributes_data; } return 0; err_release_attributes_data: release_attributes_data(); err_destroy_classdev: device_destroy(fw_attr_class, MKDEV(0, 0)); err_unregister_class: fw_attributes_class_put(); err_exit_bios_attr_pass_interface: exit_bios_attr_pass_interface(); err_exit_bios_attr_set_interface: exit_bios_attr_set_interface(); return ret; } static void __exit sysman_exit(void) { release_attributes_data(); device_destroy(fw_attr_class, MKDEV(0, 0)); fw_attributes_class_put(); exit_bios_attr_set_interface(); exit_bios_attr_pass_interface(); } module_init(sysman_init); module_exit(sysman_exit); MODULE_AUTHOR("Mario Limonciello <mario.limonciello@outlook.com>"); MODULE_AUTHOR("Prasanth Ksr <prasanth.ksr@dell.com>"); MODULE_AUTHOR("Divya Bharathi <divya.bharathi@dell.com>"); MODULE_DESCRIPTION("Dell platform setting control interface"); MODULE_LICENSE("GPL"); |