blob: 5538608bd339b8ab81f1ea31d0cfc4797d19c84d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* 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/config.h>
19#include <linux/moduleparam.h>
20#include <linux/kernel.h>
21#include <linux/string.h>
22#include <linux/errno.h>
23#include <linux/module.h>
24#include <linux/device.h>
25#include <linux/err.h>
26
27#if 0
28#define DEBUGP printk
29#else
30#define DEBUGP(fmt, a...)
31#endif
32
33static inline int dash2underscore(char c)
34{
35 if (c == '-')
36 return '_';
37 return c;
38}
39
40static 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
49static 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, &params[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. */
77static 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 /* Chew any extra spaces */
84 while (*args == ' ') args++;
85 if (*args == '"') {
86 args++;
87 in_quote = 1;
88 quoted = 1;
89 }
90
91 for (i = 0; args[i]; i++) {
92 if (args[i] == ' ' && !in_quote)
93 break;
94 if (equals == 0) {
95 if (args[i] == '=')
96 equals = i;
97 }
98 if (args[i] == '"')
99 in_quote = !in_quote;
100 }
101
102 *param = args;
103 if (!equals)
104 *val = NULL;
105 else {
106 args[equals] = '\0';
107 *val = args + equals + 1;
108
109 /* Don't include quotes in value. */
110 if (**val == '"') {
111 (*val)++;
112 if (args[i-1] == '"')
113 args[i-1] = '\0';
114 }
115 if (quoted && args[i-1] == '"')
116 args[i-1] = '\0';
117 }
118
119 if (args[i]) {
120 args[i] = '\0';
121 next = args + i + 1;
122 } else
123 next = args + i;
124 return next;
125}
126
127/* Args looks like "foo=bar,bar2 baz=fuz wiz". */
128int parse_args(const char *name,
129 char *args,
130 struct kernel_param *params,
131 unsigned num,
132 int (*unknown)(char *param, char *val))
133{
134 char *param, *val;
135
136 DEBUGP("Parsing ARGS: %s\n", args);
137
138 while (*args) {
139 int ret;
140
141 args = next_arg(args, &param, &val);
142 ret = parse_one(param, val, params, num, unknown);
143 switch (ret) {
144 case -ENOENT:
145 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
146 name, param);
147 return ret;
148 case -ENOSPC:
149 printk(KERN_ERR
150 "%s: `%s' too large for parameter `%s'\n",
151 name, val ?: "", param);
152 return ret;
153 case 0:
154 break;
155 default:
156 printk(KERN_ERR
157 "%s: `%s' invalid for parameter `%s'\n",
158 name, val ?: "", param);
159 return ret;
160 }
161 }
162
163 /* All parsed OK. */
164 return 0;
165}
166
167/* Lazy bastard, eh? */
168#define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
169 int param_set_##name(const char *val, struct kernel_param *kp) \
170 { \
171 char *endp; \
172 tmptype l; \
173 \
174 if (!val) return -EINVAL; \
175 l = strtolfn(val, &endp, 0); \
176 if (endp == val || ((type)l != l)) \
177 return -EINVAL; \
178 *((type *)kp->arg) = l; \
179 return 0; \
180 } \
181 int param_get_##name(char *buffer, struct kernel_param *kp) \
182 { \
183 return sprintf(buffer, format, *((type *)kp->arg)); \
184 }
185
186STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, simple_strtoul);
187STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol);
188STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul);
189STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol);
190STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul);
191STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol);
192STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul);
193
194int param_set_charp(const char *val, struct kernel_param *kp)
195{
196 if (!val) {
197 printk(KERN_ERR "%s: string parameter expected\n",
198 kp->name);
199 return -EINVAL;
200 }
201
202 if (strlen(val) > 1024) {
203 printk(KERN_ERR "%s: string parameter too long\n",
204 kp->name);
205 return -ENOSPC;
206 }
207
208 *(char **)kp->arg = (char *)val;
209 return 0;
210}
211
212int param_get_charp(char *buffer, struct kernel_param *kp)
213{
214 return sprintf(buffer, "%s", *((char **)kp->arg));
215}
216
217int param_set_bool(const char *val, struct kernel_param *kp)
218{
219 /* No equals means "set"... */
220 if (!val) val = "1";
221
222 /* One of =[yYnN01] */
223 switch (val[0]) {
224 case 'y': case 'Y': case '1':
225 *(int *)kp->arg = 1;
226 return 0;
227 case 'n': case 'N': case '0':
228 *(int *)kp->arg = 0;
229 return 0;
230 }
231 return -EINVAL;
232}
233
234int param_get_bool(char *buffer, struct kernel_param *kp)
235{
236 /* Y and N chosen as being relatively non-coder friendly */
237 return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N');
238}
239
240int param_set_invbool(const char *val, struct kernel_param *kp)
241{
242 int boolval, ret;
243 struct kernel_param dummy = { .arg = &boolval };
244
245 ret = param_set_bool(val, &dummy);
246 if (ret == 0)
247 *(int *)kp->arg = !boolval;
248 return ret;
249}
250
251int param_get_invbool(char *buffer, struct kernel_param *kp)
252{
253 int val;
254 struct kernel_param dummy = { .arg = &val };
255
256 val = !*(int *)kp->arg;
257 return param_get_bool(buffer, &dummy);
258}
259
260/* We cheat here and temporarily mangle the string. */
261int param_array(const char *name,
262 const char *val,
263 unsigned int min, unsigned int max,
264 void *elem, int elemsize,
265 int (*set)(const char *, struct kernel_param *kp),
266 int *num)
267{
268 int ret;
269 struct kernel_param kp;
270 char save;
271
272 /* Get the name right for errors. */
273 kp.name = name;
274 kp.arg = elem;
275
276 /* No equals sign? */
277 if (!val) {
278 printk(KERN_ERR "%s: expects arguments\n", name);
279 return -EINVAL;
280 }
281
282 *num = 0;
283 /* We expect a comma-separated list of values. */
284 do {
285 int len;
286
287 if (*num == max) {
288 printk(KERN_ERR "%s: can only take %i arguments\n",
289 name, max);
290 return -EINVAL;
291 }
292 len = strcspn(val, ",");
293
294 /* nul-terminate and parse */
295 save = val[len];
296 ((char *)val)[len] = '\0';
297 ret = set(val, &kp);
298
299 if (ret != 0)
300 return ret;
301 kp.arg += elemsize;
302 val += len+1;
303 (*num)++;
304 } while (save == ',');
305
306 if (*num < min) {
307 printk(KERN_ERR "%s: needs at least %i arguments\n",
308 name, min);
309 return -EINVAL;
310 }
311 return 0;
312}
313
314int param_array_set(const char *val, struct kernel_param *kp)
315{
316 struct kparam_array *arr = kp->arg;
317
318 return param_array(kp->name, val, 1, arr->max, arr->elem,
319 arr->elemsize, arr->set, arr->num ?: &arr->max);
320}
321
322int param_array_get(char *buffer, struct kernel_param *kp)
323{
324 int i, off, ret;
325 struct kparam_array *arr = kp->arg;
326 struct kernel_param p;
327
328 p = *kp;
329 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
330 if (i)
331 buffer[off++] = ',';
332 p.arg = arr->elem + arr->elemsize * i;
333 ret = arr->get(buffer + off, &p);
334 if (ret < 0)
335 return ret;
336 off += ret;
337 }
338 buffer[off] = '\0';
339 return off;
340}
341
342int param_set_copystring(const char *val, struct kernel_param *kp)
343{
344 struct kparam_string *kps = kp->arg;
345
346 if (strlen(val)+1 > kps->maxlen) {
347 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
348 kp->name, kps->maxlen-1);
349 return -ENOSPC;
350 }
351 strcpy(kps->string, val);
352 return 0;
353}
354
355int param_get_string(char *buffer, struct kernel_param *kp)
356{
357 struct kparam_string *kps = kp->arg;
358 return strlcpy(buffer, kps->string, kps->maxlen);
359}
360
361/* sysfs output in /sys/modules/XYZ/parameters/ */
362
363extern struct kernel_param __start___param[], __stop___param[];
364
365#define MAX_KBUILD_MODNAME KOBJ_NAME_LEN
366
367struct param_attribute
368{
369 struct module_attribute mattr;
370 struct kernel_param *param;
371};
372
373struct module_param_attrs
374{
375 struct attribute_group grp;
376 struct param_attribute attrs[0];
377};
378
379#define to_param_attr(n) container_of(n, struct param_attribute, mattr);
380
381static ssize_t param_attr_show(struct module_attribute *mattr,
382 struct module *mod, char *buf)
383{
384 int count;
385 struct param_attribute *attribute = to_param_attr(mattr);
386
387 if (!attribute->param->get)
388 return -EPERM;
389
390 count = attribute->param->get(buf, attribute->param);
391 if (count > 0) {
392 strcat(buf, "\n");
393 ++count;
394 }
395 return count;
396}
397
398/* sysfs always hands a nul-terminated string in buf. We rely on that. */
399static ssize_t param_attr_store(struct module_attribute *mattr,
400 struct module *owner,
401 const char *buf, size_t len)
402{
403 int err;
404 struct param_attribute *attribute = to_param_attr(mattr);
405
406 if (!attribute->param->set)
407 return -EPERM;
408
409 err = attribute->param->set(buf, attribute->param);
410 if (!err)
411 return len;
412 return err;
413}
414
415#ifdef CONFIG_MODULES
416#define __modinit
417#else
418#define __modinit __init
419#endif
420
421/*
422 * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME
423 * @mk: struct module_kobject (contains parent kobject)
424 * @kparam: array of struct kernel_param, the actual parameter definitions
425 * @num_params: number of entries in array
426 * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules"
427 *
428 * Create a kobject for a (per-module) group of parameters, and create files
429 * in sysfs. A pointer to the param_kobject is returned on success,
430 * NULL if there's no parameter to export, or other ERR_PTR(err).
431 */
432static __modinit struct module_param_attrs *
433param_sysfs_setup(struct module_kobject *mk,
434 struct kernel_param *kparam,
435 unsigned int num_params,
436 unsigned int name_skip)
437{
438 struct module_param_attrs *mp;
439 unsigned int valid_attrs = 0;
440 unsigned int i, size[2];
441 struct param_attribute *pattr;
442 struct attribute **gattr;
443 int err;
444
445 for (i=0; i<num_params; i++) {
446 if (kparam[i].perm)
447 valid_attrs++;
448 }
449
450 if (!valid_attrs)
451 return NULL;
452
453 size[0] = ALIGN(sizeof(*mp) +
454 valid_attrs * sizeof(mp->attrs[0]),
455 sizeof(mp->grp.attrs[0]));
456 size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]);
457
458 mp = kmalloc(size[0] + size[1], GFP_KERNEL);
459 if (!mp)
460 return ERR_PTR(-ENOMEM);
461
462 mp->grp.name = "parameters";
463 mp->grp.attrs = (void *)mp + size[0];
464
465 pattr = &mp->attrs[0];
466 gattr = &mp->grp.attrs[0];
467 for (i = 0; i < num_params; i++) {
468 struct kernel_param *kp = &kparam[i];
469 if (kp->perm) {
470 pattr->param = kp;
471 pattr->mattr.show = param_attr_show;
472 pattr->mattr.store = param_attr_store;
473 pattr->mattr.attr.name = (char *)&kp->name[name_skip];
474 pattr->mattr.attr.owner = mk->mod;
475 pattr->mattr.attr.mode = kp->perm;
476 *(gattr++) = &(pattr++)->mattr.attr;
477 }
478 }
479 *gattr = NULL;
480
481 if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) {
482 kfree(mp);
483 return ERR_PTR(err);
484 }
485 return mp;
486}
487
488
489#ifdef CONFIG_MODULES
490
491/*
492 * module_param_sysfs_setup - setup sysfs support for one module
493 * @mod: module
494 * @kparam: module parameters (array)
495 * @num_params: number of module parameters
496 *
497 * Adds sysfs entries for module parameters, and creates a link from
498 * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/
499 */
500int module_param_sysfs_setup(struct module *mod,
501 struct kernel_param *kparam,
502 unsigned int num_params)
503{
504 struct module_param_attrs *mp;
505
506 mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0);
507 if (IS_ERR(mp))
508 return PTR_ERR(mp);
509
510 mod->param_attrs = mp;
511 return 0;
512}
513
514/*
515 * module_param_sysfs_remove - remove sysfs support for one module
516 * @mod: module
517 *
518 * Remove sysfs entries for module parameters and the corresponding
519 * kobject.
520 */
521void module_param_sysfs_remove(struct module *mod)
522{
523 if (mod->param_attrs) {
524 sysfs_remove_group(&mod->mkobj.kobj,
525 &mod->param_attrs->grp);
526 /* We are positive that no one is using any param
527 * attrs at this point. Deallocate immediately. */
528 kfree(mod->param_attrs);
529 mod->param_attrs = NULL;
530 }
531}
532#endif
533
534/*
535 * kernel_param_sysfs_setup - wrapper for built-in params support
536 */
537static void __init kernel_param_sysfs_setup(const char *name,
538 struct kernel_param *kparam,
539 unsigned int num_params,
540 unsigned int name_skip)
541{
542 struct module_kobject *mk;
543
544 mk = kmalloc(sizeof(struct module_kobject), GFP_KERNEL);
545 memset(mk, 0, sizeof(struct module_kobject));
546
547 mk->mod = THIS_MODULE;
548 kobj_set_kset_s(mk, module_subsys);
549 kobject_set_name(&mk->kobj, name);
550 kobject_register(&mk->kobj);
551
552 /* no need to keep the kobject if no parameter is exported */
553 if (!param_sysfs_setup(mk, kparam, num_params, name_skip)) {
554 kobject_unregister(&mk->kobj);
555 kfree(mk);
556 }
557}
558
559/*
560 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
561 *
562 * Add module_parameters to sysfs for "modules" built into the kernel.
563 *
564 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
565 * "parameter" name is stored behind a dot in kernel_param->name. So,
566 * extract the "module" name for all built-in kernel_param-eters,
567 * and for all who have the same, call kernel_param_sysfs_setup.
568 */
569static void __init param_sysfs_builtin(void)
570{
571 struct kernel_param *kp, *kp_begin = NULL;
572 unsigned int i, name_len, count = 0;
573 char modname[MAX_KBUILD_MODNAME + 1] = "";
574
575 for (i=0; i < __stop___param - __start___param; i++) {
576 char *dot;
577
578 kp = &__start___param[i];
579
580 /* We do not handle args without periods. */
581 dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME);
582 if (!dot) {
583 DEBUGP("couldn't find period in %s\n", kp->name);
584 continue;
585 }
586 name_len = dot - kp->name;
587
588 /* new kbuild_modname? */
589 if (strlen(modname) != name_len
590 || strncmp(modname, kp->name, name_len) != 0) {
591 /* add a new kobject for previous kernel_params. */
592 if (count)
593 kernel_param_sysfs_setup(modname,
594 kp_begin,
595 count,
596 strlen(modname)+1);
597
598 strncpy(modname, kp->name, name_len);
599 modname[name_len] = '\0';
600 count = 0;
601 kp_begin = kp;
602 }
603 count++;
604 }
605
606 /* last kernel_params need to be registered as well */
607 if (count)
608 kernel_param_sysfs_setup(modname, kp_begin, count,
609 strlen(modname)+1);
610}
611
612
613/* module-related sysfs stuff */
614#ifdef CONFIG_MODULES
615
616#define to_module_attr(n) container_of(n, struct module_attribute, attr);
617#define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
618
619static ssize_t module_attr_show(struct kobject *kobj,
620 struct attribute *attr,
621 char *buf)
622{
623 struct module_attribute *attribute;
624 struct module_kobject *mk;
625 int ret;
626
627 attribute = to_module_attr(attr);
628 mk = to_module_kobject(kobj);
629
630 if (!attribute->show)
631 return -EPERM;
632
633 if (!try_module_get(mk->mod))
634 return -ENODEV;
635
636 ret = attribute->show(attribute, mk->mod, buf);
637
638 module_put(mk->mod);
639
640 return ret;
641}
642
643static ssize_t module_attr_store(struct kobject *kobj,
644 struct attribute *attr,
645 const char *buf, size_t len)
646{
647 struct module_attribute *attribute;
648 struct module_kobject *mk;
649 int ret;
650
651 attribute = to_module_attr(attr);
652 mk = to_module_kobject(kobj);
653
654 if (!attribute->store)
655 return -EPERM;
656
657 if (!try_module_get(mk->mod))
658 return -ENODEV;
659
660 ret = attribute->store(attribute, mk->mod, buf, len);
661
662 module_put(mk->mod);
663
664 return ret;
665}
666
667static struct sysfs_ops module_sysfs_ops = {
668 .show = module_attr_show,
669 .store = module_attr_store,
670};
671
672#else
673static struct sysfs_ops module_sysfs_ops = {
674 .show = NULL,
675 .store = NULL,
676};
677#endif
678
679static struct kobj_type module_ktype = {
680 .sysfs_ops = &module_sysfs_ops,
681};
682
683decl_subsys(module, &module_ktype, NULL);
684
685/*
686 * param_sysfs_init - wrapper for built-in params support
687 */
688static int __init param_sysfs_init(void)
689{
690 subsystem_register(&module_subsys);
691
692 param_sysfs_builtin();
693
694 return 0;
695}
696__initcall(param_sysfs_init);
697
698EXPORT_SYMBOL(param_set_byte);
699EXPORT_SYMBOL(param_get_byte);
700EXPORT_SYMBOL(param_set_short);
701EXPORT_SYMBOL(param_get_short);
702EXPORT_SYMBOL(param_set_ushort);
703EXPORT_SYMBOL(param_get_ushort);
704EXPORT_SYMBOL(param_set_int);
705EXPORT_SYMBOL(param_get_int);
706EXPORT_SYMBOL(param_set_uint);
707EXPORT_SYMBOL(param_get_uint);
708EXPORT_SYMBOL(param_set_long);
709EXPORT_SYMBOL(param_get_long);
710EXPORT_SYMBOL(param_set_ulong);
711EXPORT_SYMBOL(param_get_ulong);
712EXPORT_SYMBOL(param_set_charp);
713EXPORT_SYMBOL(param_get_charp);
714EXPORT_SYMBOL(param_set_bool);
715EXPORT_SYMBOL(param_get_bool);
716EXPORT_SYMBOL(param_set_invbool);
717EXPORT_SYMBOL(param_get_invbool);
718EXPORT_SYMBOL(param_array_set);
719EXPORT_SYMBOL(param_array_get);
720EXPORT_SYMBOL(param_set_copystring);
721EXPORT_SYMBOL(param_get_string);