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 tmptype l; \
184 int ret; \
185 \
186 if (!val) return -EINVAL; \
187 ret = strtolfn(val, 0, &l); \
188 if (ret == -EINVAL || ((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, strict_strtoul);
199 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
200 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
201 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
202 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
203 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
204 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_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 /* This is a hack. We can't need to strdup in early boot, and we
221 * don't need to; this mangled commandline is preserved. */
222 if (slab_is_available()) {
223 *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
224 if (!*(char **)kp->arg)
225 return -ENOMEM;
226 } else
227 *(const char **)kp->arg = val;
228
229 return 0;
230 }
231
232 int param_get_charp(char *buffer, struct kernel_param *kp)
233 {
234 return sprintf(buffer, "%s", *((char **)kp->arg));
235 }
236
237 /* Actually could be a bool or an int, for historical reasons. */
238 int param_set_bool(const char *val, struct kernel_param *kp)
239 {
240 bool v;
241
242 /* No equals means "set"... */
243 if (!val) val = "1";
244
245 /* One of =[yYnN01] */
246 switch (val[0]) {
247 case 'y': case 'Y': case '1':
248 v = true;
249 break;
250 case 'n': case 'N': case '':
251 v = false;
252 break;
253 default:
254 return -EINVAL;
255 }
256
257 if (kp->flags & KPARAM_ISBOOL)
258 *(bool *)kp->arg = v;
259 else
260 *(int *)kp->arg = v;
261 return 0;
262 }
263
264 int param_get_bool(char *buffer, struct kernel_param *kp)
265 {
266 bool val;
267 if (kp->flags & KPARAM_ISBOOL)
268 val = *(bool *)kp->arg;
269 else
270 val = *(int *)kp->arg;
271
272 /* Y and N chosen as being relatively non-coder friendly */
273 return sprintf(buffer, "%c", val ? 'Y' : 'N');
274 }
275
276 /* This one must be bool. */
277 int param_set_invbool(const char *val, struct kernel_param *kp)
278 {
279 int ret;
280 bool boolval;
281 struct kernel_param dummy;
282
283 dummy.arg = &boolval;
284 dummy.flags = KPARAM_ISBOOL;
285 ret = param_set_bool(val, &dummy);
286 if (ret == 0)
287 *(bool *)kp->arg = !boolval;
288 return ret;
289 }
290
291 int param_get_invbool(char *buffer, struct kernel_param *kp)
292 {
293 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
294 }
295
296 /* We break the rule and mangle the string. */
297 static int param_array(const char *name,
298 const char *val,
299 unsigned int min, unsigned int max,
300 void *elem, int elemsize,
301 int (*set)(const char *, struct kernel_param *kp),
302 u16 flags,
303 unsigned int *num)
304 {
305 int ret;
306 struct kernel_param kp;
307 char save;
308
309 /* Get the name right for errors. */
310 kp.name = name;
311 kp.arg = elem;
312 kp.flags = flags;
313
314 /* No equals sign? */
315 if (!val) {
316 printk(KERN_ERR "%s: expects arguments\n", name);
317 return -EINVAL;
318 }
319
320 *num = 0;
321 /* We expect a comma-separated list of values. */
322 do {
323 int len;
324
325 if (*num == max) {
326 printk(KERN_ERR "%s: can only take %i arguments\n",
327 name, max);
328 return -EINVAL;
329 }
330 len = strcspn(val, ",");
331
332 /* nul-terminate and parse */
333 save = val[len];
334 ((char *)val)[len] = '\0';
335 ret = set(val, &kp);
336
337 if (ret != 0)
338 return ret;
339 kp.arg += elemsize;
340 val += len+1;
341 (*num)++;
342 } while (save == ',');
343
344 if (*num < min) {
345 printk(KERN_ERR "%s: needs at least %i arguments\n",
346 name, min);
347 return -EINVAL;
348 }
349 return 0;
350 }
351
352 int param_array_set(const char *val, struct kernel_param *kp)
353 {
354 const struct kparam_array *arr = kp->arr;
355 unsigned int temp_num;
356
357 return param_array(kp->name, val, 1, arr->max, arr->elem,
358 arr->elemsize, arr->set, kp->flags,
359 arr->num ?: &temp_num);
360 }
361
362 int param_array_get(char *buffer, struct kernel_param *kp)
363 {
364 int i, off, ret;
365 const struct kparam_array *arr = kp->arr;
366 struct kernel_param p;
367
368 p = *kp;
369 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
370 if (i)
371 buffer[off++] = ',';
372 p.arg = arr->elem + arr->elemsize * i;
373 ret = arr->get(buffer + off, &p);
374 if (ret < 0)
375 return ret;
376 off += ret;
377 }
378 buffer[off] = '\0';
379 return off;
380 }
381
382 int param_set_copystring(const char *val, struct kernel_param *kp)
383 {
384 const struct kparam_string *kps = kp->str;
385
386 if (!val) {
387 printk(KERN_ERR "%s: missing param set value\n", kp->name);
388 return -EINVAL;
389 }
390 if (strlen(val)+1 > kps->maxlen) {
391 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
392 kp->name, kps->maxlen-1);
393 return -ENOSPC;
394 }
395 strcpy(kps->string, val);
396 return 0;
397 }
398
399 int param_get_string(char *buffer, struct kernel_param *kp)
400 {
401 const struct kparam_string *kps = kp->str;
402 return strlcpy(buffer, kps->string, kps->maxlen);
403 }
404
405 /* sysfs output in /sys/modules/XYZ/parameters/ */
406 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
407 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
408
409 extern struct kernel_param __start___param[], __stop___param[];
410
411 struct param_attribute
412 {
413 struct module_attribute mattr;
414 struct kernel_param *param;
415 };
416
417 struct module_param_attrs
418 {
419 unsigned int num;
420 struct attribute_group grp;
421 struct param_attribute attrs[0];
422 };
423
424 #ifdef CONFIG_SYSFS
425 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
426
427 static ssize_t param_attr_show(struct module_attribute *mattr,
428 struct module *mod, char *buf)
429 {
430 int count;
431 struct param_attribute *attribute = to_param_attr(mattr);
432
433 if (!attribute->param->get)
434 return -EPERM;
435
436 count = attribute->param->get(buf, attribute->param);
437 if (count > 0) {
438 strcat(buf, "\n");
439 ++count;
440 }
441 return count;
442 }
443
444 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
445 static ssize_t param_attr_store(struct module_attribute *mattr,
446 struct module *owner,
447 const char *buf, size_t len)
448 {
449 int err;
450 struct param_attribute *attribute = to_param_attr(mattr);
451
452 if (!attribute->param->set)
453 return -EPERM;
454
455 err = attribute->param->set(buf, attribute->param);
456 if (!err)
457 return len;
458 return err;
459 }
460 #endif
461
462 #ifdef CONFIG_MODULES
463 #define __modinit
464 #else
465 #define __modinit __init
466 #endif
467
468 #ifdef CONFIG_SYSFS
469 /*
470 * add_sysfs_param - add a parameter to sysfs
471 * @mk: struct module_kobject
472 * @kparam: the actual parameter definition to add to sysfs
473 * @name: name of parameter
474 *
475 * Create a kobject if for a (per-module) parameter if mp NULL, and
476 * create file in sysfs. Returns an error on out of memory. Always cleans up
477 * if there's an error.
478 */
479 static __modinit int add_sysfs_param(struct module_kobject *mk,
480 struct kernel_param *kp,
481 const char *name)
482 {
483 struct module_param_attrs *new;
484 struct attribute **attrs;
485 int err, num;
486
487 /* We don't bother calling this with invisible parameters. */
488 BUG_ON(!kp->perm);
489
490 if (!mk->mp) {
491 num = 0;
492 attrs = NULL;
493 } else {
494 num = mk->mp->num;
495 attrs = mk->mp->grp.attrs;
496 }
497
498 /* Enlarge. */
499 new = krealloc(mk->mp,
500 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
501 GFP_KERNEL);
502 if (!new) {
503 kfree(mk->mp);
504 err = -ENOMEM;
505 goto fail;
506 }
507 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
508 if (!attrs) {
509 err = -ENOMEM;
510 goto fail_free_new;
511 }
512
513 /* Sysfs wants everything zeroed. */
514 memset(new, 0, sizeof(*new));
515 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
516 memset(&attrs[num], 0, sizeof(attrs[num]));
517 new->grp.name = "parameters";
518 new->grp.attrs = attrs;
519
520 /* Tack new one on the end. */
521 new->attrs[num].param = kp;
522 new->attrs[num].mattr.show = param_attr_show;
523 new->attrs[num].mattr.store = param_attr_store;
524 new->attrs[num].mattr.attr.name = (char *)name;
525 new->attrs[num].mattr.attr.mode = kp->perm;
526 new->num = num+1;
527
528 /* Fix up all the pointers, since krealloc can move us */
529 for (num = 0; num < new->num; num++)
530 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
531 new->grp.attrs[num] = NULL;
532
533 mk->mp = new;
534 return 0;
535
536 fail_free_new:
537 kfree(new);
538 fail:
539 mk->mp = NULL;
540 return err;
541 }
542
543 #ifdef CONFIG_MODULES
544 static void free_module_param_attrs(struct module_kobject *mk)
545 {
546 kfree(mk->mp->grp.attrs);
547 kfree(mk->mp);
548 mk->mp = NULL;
549 }
550
551 /*
552 * module_param_sysfs_setup - setup sysfs support for one module
553 * @mod: module
554 * @kparam: module parameters (array)
555 * @num_params: number of module parameters
556 *
557 * Adds sysfs entries for module parameters under
558 * /sys/module/[mod->name]/parameters/
559 */
560 int module_param_sysfs_setup(struct module *mod,
561 struct kernel_param *kparam,
562 unsigned int num_params)
563 {
564 int i, err;
565 bool params = false;
566
567 for (i = 0; i < num_params; i++) {
568 if (kparam[i].perm == 0)
569 continue;
570 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
571 if (err)
572 return err;
573 params = true;
574 }
575
576 if (!params)
577 return 0;
578
579 /* Create the param group. */
580 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
581 if (err)
582 free_module_param_attrs(&mod->mkobj);
583 return err;
584 }
585
586 /*
587 * module_param_sysfs_remove - remove sysfs support for one module
588 * @mod: module
589 *
590 * Remove sysfs entries for module parameters and the corresponding
591 * kobject.
592 */
593 void module_param_sysfs_remove(struct module *mod)
594 {
595 if (mod->mkobj.mp) {
596 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
597 /* We are positive that no one is using any param
598 * attrs at this point. Deallocate immediately. */
599 free_module_param_attrs(&mod->mkobj);
600 }
601 }
602 #endif
603
604 void destroy_params(const struct kernel_param *params, unsigned num)
605 {
606 /* FIXME: This should free kmalloced charp parameters. It doesn't. */
607 }
608
609 static void __init kernel_add_sysfs_param(const char *name,
610 struct kernel_param *kparam,
611 unsigned int name_skip)
612 {
613 struct module_kobject *mk;
614 struct kobject *kobj;
615 int err;
616
617 kobj = kset_find_obj(module_kset, name);
618 if (kobj) {
619 /* We already have one. Remove params so we can add more. */
620 mk = to_module_kobject(kobj);
621 /* We need to remove it before adding parameters. */
622 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
623 } else {
624 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
625 BUG_ON(!mk);
626
627 mk->mod = THIS_MODULE;
628 mk->kobj.kset = module_kset;
629 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
630 "%s", name);
631 if (err) {
632 kobject_put(&mk->kobj);
633 printk(KERN_ERR "Module '%s' failed add to sysfs, "
634 "error number %d\n", name, err);
635 printk(KERN_ERR "The system will be unstable now.\n");
636 return;
637 }
638 /* So that exit path is even. */
639 kobject_get(&mk->kobj);
640 }
641
642 /* These should not fail at boot. */
643 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
644 BUG_ON(err);
645 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
646 BUG_ON(err);
647 kobject_uevent(&mk->kobj, KOBJ_ADD);
648 kobject_put(&mk->kobj);
649 }
650
651 /*
652 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
653 *
654 * Add module_parameters to sysfs for "modules" built into the kernel.
655 *
656 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
657 * "parameter" name is stored behind a dot in kernel_param->name. So,
658 * extract the "module" name for all built-in kernel_param-eters,
659 * and for all who have the same, call kernel_add_sysfs_param.
660 */
661 static void __init param_sysfs_builtin(void)
662 {
663 struct kernel_param *kp;
664 unsigned int name_len;
665 char modname[MODULE_NAME_LEN];
666
667 for (kp = __start___param; kp < __stop___param; kp++) {
668 char *dot;
669
670 if (kp->perm == 0)
671 continue;
672
673 dot = strchr(kp->name, '.');
674 if (!dot) {
675 /* This happens for core_param() */
676 strcpy(modname, "kernel");
677 name_len = 0;
678 } else {
679 name_len = dot - kp->name + 1;
680 strlcpy(modname, kp->name, name_len);
681 }
682 kernel_add_sysfs_param(modname, kp, name_len);
683 }
684 }
685
686
687 /* module-related sysfs stuff */
688
689 static ssize_t module_attr_show(struct kobject *kobj,
690 struct attribute *attr,
691 char *buf)
692 {
693 struct module_attribute *attribute;
694 struct module_kobject *mk;
695 int ret;
696
697 attribute = to_module_attr(attr);
698 mk = to_module_kobject(kobj);
699
700 if (!attribute->show)
701 return -EIO;
702
703 ret = attribute->show(attribute, mk->mod, buf);
704
705 return ret;
706 }
707
708 static ssize_t module_attr_store(struct kobject *kobj,
709 struct attribute *attr,
710 const char *buf, size_t len)
711 {
712 struct module_attribute *attribute;
713 struct module_kobject *mk;
714 int ret;
715
716 attribute = to_module_attr(attr);
717 mk = to_module_kobject(kobj);
718
719 if (!attribute->store)
720 return -EIO;
721
722 ret = attribute->store(attribute, mk->mod, buf, len);
723
724 return ret;
725 }
726
727 static struct sysfs_ops module_sysfs_ops = {
728 .show = module_attr_show,
729 .store = module_attr_store,
730 };
731
732 static int uevent_filter(struct kset *kset, struct kobject *kobj)
733 {
734 struct kobj_type *ktype = get_ktype(kobj);
735
736 if (ktype == &module_ktype)
737 return 1;
738 return 0;
739 }
740
741 static struct kset_uevent_ops module_uevent_ops = {
742 .filter = uevent_filter,
743 };
744
745 struct kset *module_kset;
746 int module_sysfs_initialized;
747
748 struct kobj_type module_ktype = {
749 .sysfs_ops = &module_sysfs_ops,
750 };
751
752 /*
753 * param_sysfs_init - wrapper for built-in params support
754 */
755 static int __init param_sysfs_init(void)
756 {
757 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
758 if (!module_kset) {
759 printk(KERN_WARNING "%s (%d): error creating kset\n",
760 __FILE__, __LINE__);
761 return -ENOMEM;
762 }
763 module_sysfs_initialized = 1;
764
765 param_sysfs_builtin();
766
767 return 0;
768 }
769 subsys_initcall(param_sysfs_init);
770
771 #endif /* CONFIG_SYSFS */
772
773 EXPORT_SYMBOL(param_set_byte);
774 EXPORT_SYMBOL(param_get_byte);
775 EXPORT_SYMBOL(param_set_short);
776 EXPORT_SYMBOL(param_get_short);
777 EXPORT_SYMBOL(param_set_ushort);
778 EXPORT_SYMBOL(param_get_ushort);
779 EXPORT_SYMBOL(param_set_int);
780 EXPORT_SYMBOL(param_get_int);
781 EXPORT_SYMBOL(param_set_uint);
782 EXPORT_SYMBOL(param_get_uint);
783 EXPORT_SYMBOL(param_set_long);
784 EXPORT_SYMBOL(param_get_long);
785 EXPORT_SYMBOL(param_set_ulong);
786 EXPORT_SYMBOL(param_get_ulong);
787 EXPORT_SYMBOL(param_set_charp);
788 EXPORT_SYMBOL(param_get_charp);
789 EXPORT_SYMBOL(param_set_bool);
790 EXPORT_SYMBOL(param_get_bool);
791 EXPORT_SYMBOL(param_set_invbool);
792 EXPORT_SYMBOL(param_get_invbool);
793 EXPORT_SYMBOL(param_array_set);
794 EXPORT_SYMBOL(param_array_get);
795 EXPORT_SYMBOL(param_set_copystring);
796 EXPORT_SYMBOL(param_get_string);
797
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