1 /* Helpers for initial module or kernel cmdline parsing 2 Copyright (C) 2001 Rusty Russell. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 2 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; if not, write to the Free Software 16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 */ 18 #include <linux/moduleparam.h> 19 #include <linux/kernel.h> 20 #include <linux/string.h> 21 #include <linux/errno.h> 22 #include <linux/module.h> 23 #include <linux/device.h> 24 #include <linux/err.h> 25 #include <linux/slab.h> 26 27 #if 0 28 #define DEBUGP printk 29 #else 30 #define DEBUGP(fmt, a...) 31 #endif 32 33 static inline char dash2underscore(char c) 34 { 35 if (c == '-') 36 return '_'; 37 return c; 38 } 39 40 static inline int parameq(const char *input, const char *paramname) 41 { 42 unsigned int i; 43 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++) 44 if (input[i] == '\0') 45 return 1; 46 return 0; 47 } 48 49 static int parse_one(char *param, 50 char *val, 51 struct kernel_param *params, 52 unsigned num_params, 53 int (*handle_unknown)(char *param, char *val)) 54 { 55 unsigned int i; 56 57 /* Find parameter */ 58 for (i = 0; i < num_params; i++) { 59 if (parameq(param, params[i].name)) { 60 DEBUGP("They are equal! Calling %p\n", 61 params[i].set); 62 return params[i].set(val, ¶ms[i]); 63 } 64 } 65 66 if (handle_unknown) { 67 DEBUGP("Unknown argument: calling %p\n", handle_unknown); 68 return handle_unknown(param, val); 69 } 70 71 DEBUGP("Unknown argument `%s'\n", param); 72 return -ENOENT; 73 } 74 75 /* You can use " around spaces, but can't escape ". */ 76 /* Hyphens and underscores equivalent in parameter names. */ 77 static char *next_arg(char *args, char **param, char **val) 78 { 79 unsigned int i, equals = 0; 80 int in_quote = 0, quoted = 0; 81 char *next; 82 83 if (*args == '"') { 84 args++; 85 in_quote = 1; 86 quoted = 1; 87 } 88 89 for (i = 0; args[i]; i++) { 90 if (args[i] == ' ' && !in_quote) 91 break; 92 if (equals == 0) { 93 if (args[i] == '=') 94 equals = i; 95 } 96 if (args[i] == '"') 97 in_quote = !in_quote; 98 } 99 100 *param = args; 101 if (!equals) 102 *val = NULL; 103 else { 104 args[equals] = '\0'; 105 *val = args + equals + 1; 106 107 /* Don't include quotes in value. */ 108 if (**val == '"') { 109 (*val)++; 110 if (args[i-1] == '"') 111 args[i-1] = '\0'; 112 } 113 if (quoted && args[i-1] == '"') 114 args[i-1] = '\0'; 115 } 116 117 if (args[i]) { 118 args[i] = '\0'; 119 next = args + i + 1; 120 } else 121 next = args + i; 122 123 /* Chew up trailing spaces. */ 124 while (*next == ' ') 125 next++; 126 return next; 127 } 128 129 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ 130 int parse_args(const char *name, 131 char *args, 132 struct kernel_param *params, 133 unsigned num, 134 int (*unknown)(char *param, char *val)) 135 { 136 char *param, *val; 137 138 DEBUGP("Parsing ARGS: %s\n", args); 139 140 /* Chew leading spaces */ 141 while (*args == ' ') 142 args++; 143 144 while (*args) { 145 int ret; 146 int irq_was_disabled; 147 148 args = next_arg(args, ¶m, &val); 149 irq_was_disabled = irqs_disabled(); 150 ret = parse_one(param, val, params, num, unknown); 151 if (irq_was_disabled && !irqs_disabled()) { 152 printk(KERN_WARNING "parse_args(): option '%s' enabled " 153 "irq's!\n", param); 154 } 155 switch (ret) { 156 case -ENOENT: 157 printk(KERN_ERR "%s: Unknown parameter `%s'\n", 158 name, param); 159 return ret; 160 case -ENOSPC: 161 printk(KERN_ERR 162 "%s: `%s' too large for parameter `%s'\n", 163 name, val ?: "", param); 164 return ret; 165 case 0: 166 break; 167 default: 168 printk(KERN_ERR 169 "%s: `%s' invalid for parameter `%s'\n", 170 name, val ?: "", param); 171 return ret; 172 } 173 } 174 175 /* All parsed OK. */ 176 return 0; 177 } 178 179 /* Lazy bastard, eh? */ 180 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \ 181 int param_set_##name(const char *val, struct kernel_param *kp) \ 182 { \ 183 char *endp; \ 184 tmptype l; \ 185 \ 186 if (!val) return -EINVAL; \ 187 l = strtolfn(val, &endp, 0); \ 188 if (endp == val || ((type)l != l)) \ 189 return -EINVAL; \ 190 *((type *)kp->arg) = l; \ 191 return 0; \ 192 } \ 193 int param_get_##name(char *buffer, struct kernel_param *kp) \ 194 { \ 195 return sprintf(buffer, format, *((type *)kp->arg)); \ 196 } 197 198 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, simple_strtoul); 199 STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol); 200 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul); 201 STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol); 202 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul); 203 STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol); 204 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul); 205 206 int param_set_charp(const char *val, struct kernel_param *kp) 207 { 208 if (!val) { 209 printk(KERN_ERR "%s: string parameter expected\n", 210 kp->name); 211 return -EINVAL; 212 } 213 214 if (strlen(val) > 1024) { 215 printk(KERN_ERR "%s: string parameter too long\n", 216 kp->name); 217 return -ENOSPC; 218 } 219 220 *(char **)kp->arg = (char *)val; 221 return 0; 222 } 223 224 int param_get_charp(char *buffer, struct kernel_param *kp) 225 { 226 return sprintf(buffer, "%s", *((char **)kp->arg)); 227 } 228 229 int param_set_bool(const char *val, struct kernel_param *kp) 230 { 231 /* No equals means "set"... */ 232 if (!val) val = "1"; 233 234 /* One of =[yYnN01] */ 235 switch (val[0]) { 236 case 'y': case 'Y': case '1': 237 *(int *)kp->arg = 1; 238 return 0; 239 case 'n': case 'N': case '0': 240 *(int *)kp->arg = 0; 241 return 0; 242 } 243 return -EINVAL; 244 } 245 246 int param_get_bool(char *buffer, struct kernel_param *kp) 247 { 248 /* Y and N chosen as being relatively non-coder friendly */ 249 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N'); 250 } 251 252 int param_set_invbool(const char *val, struct kernel_param *kp) 253 { 254 int boolval, ret; 255 struct kernel_param dummy = { .arg = &boolval }; 256 257 ret = param_set_bool(val, &dummy); 258 if (ret == 0) 259 *(int *)kp->arg = !boolval; 260 return ret; 261 } 262 263 int param_get_invbool(char *buffer, struct kernel_param *kp) 264 { 265 int val; 266 struct kernel_param dummy = { .arg = &val }; 267 268 val = !*(int *)kp->arg; 269 return param_get_bool(buffer, &dummy); 270 } 271 272 /* We cheat here and temporarily mangle the string. */ 273 static int param_array(const char *name, 274 const char *val, 275 unsigned int min, unsigned int max, 276 void *elem, int elemsize, 277 int (*set)(const char *, struct kernel_param *kp), 278 int *num) 279 { 280 int ret; 281 struct kernel_param kp; 282 char save; 283 284 /* Get the name right for errors. */ 285 kp.name = name; 286 kp.arg = elem; 287 288 /* No equals sign? */ 289 if (!val) { 290 printk(KERN_ERR "%s: expects arguments\n", name); 291 return -EINVAL; 292 } 293 294 *num = 0; 295 /* We expect a comma-separated list of values. */ 296 do { 297 int len; 298 299 if (*num == max) { 300 printk(KERN_ERR "%s: can only take %i arguments\n", 301 name, max); 302 return -EINVAL; 303 } 304 len = strcspn(val, ","); 305 306 /* nul-terminate and parse */ 307 save = val[len]; 308 ((char *)val)[len] = '\0'; 309 ret = set(val, &kp); 310 311 if (ret != 0) 312 return ret; 313 kp.arg += elemsize; 314 val += len+1; 315 (*num)++; 316 } while (save == ','); 317 318 if (*num < min) { 319 printk(KERN_ERR "%s: needs at least %i arguments\n", 320 name, min); 321 return -EINVAL; 322 } 323 return 0; 324 } 325 326 int param_array_set(const char *val, struct kernel_param *kp) 327 { 328 struct kparam_array *arr = kp->arg; 329 unsigned int temp_num; 330 331 return param_array(kp->name, val, 1, arr->max, arr->elem, 332 arr->elemsize, arr->set, arr->num ?: &temp_num); 333 } 334 335 int param_array_get(char *buffer, struct kernel_param *kp) 336 { 337 int i, off, ret; 338 struct kparam_array *arr = kp->arg; 339 struct kernel_param p; 340 341 p = *kp; 342 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { 343 if (i) 344 buffer[off++] = ','; 345 p.arg = arr->elem + arr->elemsize * i; 346 ret = arr->get(buffer + off, &p); 347 if (ret < 0) 348 return ret; 349 off += ret; 350 } 351 buffer[off] = '\0'; 352 return off; 353 } 354 355 int param_set_copystring(const char *val, struct kernel_param *kp) 356 { 357 struct kparam_string *kps = kp->arg; 358 359 if (strlen(val)+1 > kps->maxlen) { 360 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n", 361 kp->name, kps->maxlen-1); 362 return -ENOSPC; 363 } 364 strcpy(kps->string, val); 365 return 0; 366 } 367 368 int param_get_string(char *buffer, struct kernel_param *kp) 369 { 370 struct kparam_string *kps = kp->arg; 371 return strlcpy(buffer, kps->string, kps->maxlen); 372 } 373 374 /* sysfs output in /sys/modules/XYZ/parameters/ */ 375 376 extern struct kernel_param __start___param[], __stop___param[]; 377 378 #define MAX_KBUILD_MODNAME KOBJ_NAME_LEN 379 380 struct param_attribute 381 { 382 struct module_attribute mattr; 383 struct kernel_param *param; 384 }; 385 386 struct module_param_attrs 387 { 388 struct attribute_group grp; 389 struct param_attribute attrs[0]; 390 }; 391 392 #ifdef CONFIG_SYSFS 393 #define to_param_attr(n) container_of(n, struct param_attribute, mattr); 394 395 static ssize_t param_attr_show(struct module_attribute *mattr, 396 struct module *mod, char *buf) 397 { 398 int count; 399 struct param_attribute *attribute = to_param_attr(mattr); 400 401 if (!attribute->param->get) 402 return -EPERM; 403 404 count = attribute->param->get(buf, attribute->param); 405 if (count > 0) { 406 strcat(buf, "\n"); 407 ++count; 408 } 409 return count; 410 } 411 412 /* sysfs always hands a nul-terminated string in buf. We rely on that. */ 413 static ssize_t param_attr_store(struct module_attribute *mattr, 414 struct module *owner, 415 const char *buf, size_t len) 416 { 417 int err; 418 struct param_attribute *attribute = to_param_attr(mattr); 419 420 if (!attribute->param->set) 421 return -EPERM; 422 423 err = attribute->param->set(buf, attribute->param); 424 if (!err) 425 return len; 426 return err; 427 } 428 #endif 429 430 #ifdef CONFIG_MODULES 431 #define __modinit 432 #else 433 #define __modinit __init 434 #endif 435 436 #ifdef CONFIG_SYSFS 437 /* 438 * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME 439 * @mk: struct module_kobject (contains parent kobject) 440 * @kparam: array of struct kernel_param, the actual parameter definitions 441 * @num_params: number of entries in array 442 * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules" 443 * 444 * Create a kobject for a (per-module) group of parameters, and create files 445 * in sysfs. A pointer to the param_kobject is returned on success, 446 * NULL if there's no parameter to export, or other ERR_PTR(err). 447 */ 448 static __modinit struct module_param_attrs * 449 param_sysfs_setup(struct module_kobject *mk, 450 struct kernel_param *kparam, 451 unsigned int num_params, 452 unsigned int name_skip) 453 { 454 struct module_param_attrs *mp; 455 unsigned int valid_attrs = 0; 456 unsigned int i, size[2]; 457 struct param_attribute *pattr; 458 struct attribute **gattr; 459 int err; 460 461 for (i=0; i<num_params; i++) { 462 if (kparam[i].perm) 463 valid_attrs++; 464 } 465 466 if (!valid_attrs) 467 return NULL; 468 469 size[0] = ALIGN(sizeof(*mp) + 470 valid_attrs * sizeof(mp->attrs[0]), 471 sizeof(mp->grp.attrs[0])); 472 size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]); 473 474 mp = kmalloc(size[0] + size[1], GFP_KERNEL); 475 if (!mp) 476 return ERR_PTR(-ENOMEM); 477 478 mp->grp.name = "parameters"; 479 mp->grp.attrs = (void *)mp + size[0]; 480 481 pattr = &mp->attrs[0]; 482 gattr = &mp->grp.attrs[0]; 483 for (i = 0; i < num_params; i++) { 484 struct kernel_param *kp = &kparam[i]; 485 if (kp->perm) { 486 pattr->param = kp; 487 pattr->mattr.show = param_attr_show; 488 pattr->mattr.store = param_attr_store; 489 pattr->mattr.attr.name = (char *)&kp->name[name_skip]; 490 pattr->mattr.attr.owner = mk->mod; 491 pattr->mattr.attr.mode = kp->perm; 492 *(gattr++) = &(pattr++)->mattr.attr; 493 } 494 } 495 *gattr = NULL; 496 497 if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) { 498 kfree(mp); 499 return ERR_PTR(err); 500 } 501 return mp; 502 } 503 504 #ifdef CONFIG_MODULES 505 /* 506 * module_param_sysfs_setup - setup sysfs support for one module 507 * @mod: module 508 * @kparam: module parameters (array) 509 * @num_params: number of module parameters 510 * 511 * Adds sysfs entries for module parameters, and creates a link from 512 * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/ 513 */ 514 int module_param_sysfs_setup(struct module *mod, 515 struct kernel_param *kparam, 516 unsigned int num_params) 517 { 518 struct module_param_attrs *mp; 519 520 mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0); 521 if (IS_ERR(mp)) 522 return PTR_ERR(mp); 523 524 mod->param_attrs = mp; 525 return 0; 526 } 527 528 /* 529 * module_param_sysfs_remove - remove sysfs support for one module 530 * @mod: module 531 * 532 * Remove sysfs entries for module parameters and the corresponding 533 * kobject. 534 */ 535 void module_param_sysfs_remove(struct module *mod) 536 { 537 if (mod->param_attrs) { 538 sysfs_remove_group(&mod->mkobj.kobj, 539 &mod->param_attrs->grp); 540 /* We are positive that no one is using any param 541 * attrs at this point. Deallocate immediately. */ 542 kfree(mod->param_attrs); 543 mod->param_attrs = NULL; 544 } 545 } 546 #endif 547 548 /* 549 * kernel_param_sysfs_setup - wrapper for built-in params support 550 */ 551 static void __init kernel_param_sysfs_setup(const char *name, 552 struct kernel_param *kparam, 553 unsigned int num_params, 554 unsigned int name_skip) 555 { 556 struct module_kobject *mk; 557 int ret; 558 559 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); 560 BUG_ON(!mk); 561 562 mk->mod = THIS_MODULE; 563 kobj_set_kset_s(mk, module_subsys); 564 kobject_set_name(&mk->kobj, name); 565 kobject_init(&mk->kobj); 566 ret = kobject_add(&mk->kobj); 567 BUG_ON(ret < 0); 568 param_sysfs_setup(mk, kparam, num_params, name_skip); 569 kobject_uevent(&mk->kobj, KOBJ_ADD); 570 } 571 572 /* 573 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules 574 * 575 * Add module_parameters to sysfs for "modules" built into the kernel. 576 * 577 * The "module" name (KBUILD_MODNAME) is stored before a dot, the 578 * "parameter" name is stored behind a dot in kernel_param->name. So, 579 * extract the "module" name for all built-in kernel_param-eters, 580 * and for all who have the same, call kernel_param_sysfs_setup. 581 */ 582 static void __init param_sysfs_builtin(void) 583 { 584 struct kernel_param *kp, *kp_begin = NULL; 585 unsigned int i, name_len, count = 0; 586 char modname[MAX_KBUILD_MODNAME + 1] = ""; 587 588 for (i=0; i < __stop___param - __start___param; i++) { 589 char *dot; 590 591 kp = &__start___param[i]; 592 593 /* We do not handle args without periods. */ 594 dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME); 595 if (!dot) { 596 DEBUGP("couldn't find period in %s\n", kp->name); 597 continue; 598 } 599 name_len = dot - kp->name; 600 601 /* new kbuild_modname? */ 602 if (strlen(modname) != name_len 603 || strncmp(modname, kp->name, name_len) != 0) { 604 /* add a new kobject for previous kernel_params. */ 605 if (count) 606 kernel_param_sysfs_setup(modname, 607 kp_begin, 608 count, 609 strlen(modname)+1); 610 611 strncpy(modname, kp->name, name_len); 612 modname[name_len] = '\0'; 613 count = 0; 614 kp_begin = kp; 615 } 616 count++; 617 } 618 619 /* last kernel_params need to be registered as well */ 620 if (count) 621 kernel_param_sysfs_setup(modname, kp_begin, count, 622 strlen(modname)+1); 623 } 624 625 626 /* module-related sysfs stuff */ 627 628 #define to_module_attr(n) container_of(n, struct module_attribute, attr); 629 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj); 630 631 static ssize_t module_attr_show(struct kobject *kobj, 632 struct attribute *attr, 633 char *buf) 634 { 635 struct module_attribute *attribute; 636 struct module_kobject *mk; 637 int ret; 638 639 attribute = to_module_attr(attr); 640 mk = to_module_kobject(kobj); 641 642 if (!attribute->show) 643 return -EIO; 644 645 ret = attribute->show(attribute, mk->mod, buf); 646 647 return ret; 648 } 649 650 static ssize_t module_attr_store(struct kobject *kobj, 651 struct attribute *attr, 652 const char *buf, size_t len) 653 { 654 struct module_attribute *attribute; 655 struct module_kobject *mk; 656 int ret; 657 658 attribute = to_module_attr(attr); 659 mk = to_module_kobject(kobj); 660 661 if (!attribute->store) 662 return -EIO; 663 664 ret = attribute->store(attribute, mk->mod, buf, len); 665 666 return ret; 667 } 668 669 static struct sysfs_ops module_sysfs_ops = { 670 .show = module_attr_show, 671 .store = module_attr_store, 672 }; 673 674 static struct kobj_type module_ktype; 675 676 static int uevent_filter(struct kset *kset, struct kobject *kobj) 677 { 678 struct kobj_type *ktype = get_ktype(kobj); 679 680 if (ktype == &module_ktype) 681 return 1; 682 return 0; 683 } 684 685 static struct kset_uevent_ops module_uevent_ops = { 686 .filter = uevent_filter, 687 }; 688 689 decl_subsys(module, &module_ktype, &module_uevent_ops); 690 691 static struct kobj_type module_ktype = { 692 .sysfs_ops = &module_sysfs_ops, 693 }; 694 695 /* 696 * param_sysfs_init - wrapper for built-in params support 697 */ 698 static int __init param_sysfs_init(void) 699 { 700 int ret; 701 702 ret = subsystem_register(&module_subsys); 703 if (ret < 0) { 704 printk(KERN_WARNING "%s (%d): subsystem_register error: %d\n", 705 __FILE__, __LINE__, ret); 706 return ret; 707 } 708 709 param_sysfs_builtin(); 710 711 return 0; 712 } 713 subsys_initcall(param_sysfs_init); 714 715 #else 716 #if 0 717 static struct sysfs_ops module_sysfs_ops = { 718 .show = NULL, 719 .store = NULL, 720 }; 721 #endif 722 #endif 723 724 EXPORT_SYMBOL(param_set_byte); 725 EXPORT_SYMBOL(param_get_byte); 726 EXPORT_SYMBOL(param_set_short); 727 EXPORT_SYMBOL(param_get_short); 728 EXPORT_SYMBOL(param_set_ushort); 729 EXPORT_SYMBOL(param_get_ushort); 730 EXPORT_SYMBOL(param_set_int); 731 EXPORT_SYMBOL(param_get_int); 732 EXPORT_SYMBOL(param_set_uint); 733 EXPORT_SYMBOL(param_get_uint); 734 EXPORT_SYMBOL(param_set_long); 735 EXPORT_SYMBOL(param_get_long); 736 EXPORT_SYMBOL(param_set_ulong); 737 EXPORT_SYMBOL(param_get_ulong); 738 EXPORT_SYMBOL(param_set_charp); 739 EXPORT_SYMBOL(param_get_charp); 740 EXPORT_SYMBOL(param_set_bool); 741 EXPORT_SYMBOL(param_get_bool); 742 EXPORT_SYMBOL(param_set_invbool); 743 EXPORT_SYMBOL(param_get_invbool); 744 EXPORT_SYMBOL(param_array_set); 745 EXPORT_SYMBOL(param_array_get); 746 EXPORT_SYMBOL(param_set_copystring); 747 EXPORT_SYMBOL(param_get_string); 748