/* Helpers for initial module or kernel cmdline parsing Copyright (C) 2001 Rusty Russell. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/config.h> #include <linux/moduleparam.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/module.h> #include <linux/device.h> #include <linux/err.h> #if 0 #define DEBUGP printk #else #define DEBUGP(fmt, a...) #endif static inline int dash2underscore(char c) { if (c == '-') return '_'; return c; } static inline int parameq(const char *input, const char *paramname) { unsigned int i; for (i = 0; dash2underscore(input[i]) == paramname[i]; i++) if (input[i] == '\0') return 1; return 0; } static int parse_one(char *param, char *val, struct kernel_param *params, unsigned num_params, int (*handle_unknown)(char *param, char *val)) { unsigned int i; /* Find parameter */ for (i = 0; i < num_params; i++) { if (parameq(param, params[i].name)) { DEBUGP("They are equal! Calling %p\n", params[i].set); return params[i].set(val, ¶ms[i]); } } if (handle_unknown) { DEBUGP("Unknown argument: calling %p\n", handle_unknown); return handle_unknown(param, val); } DEBUGP("Unknown argument `%s'\n", param); return -ENOENT; } /* You can use " around spaces, but can't escape ". */ /* Hyphens and underscores equivalent in parameter names. */ static char *next_arg(char *args, char **param, char **val) { unsigned int i, equals = 0; int in_quote = 0, quoted = 0; char *next; if (*args == '"') { args++; in_quote = 1; quoted = 1; } for (i = 0; args[i]; i++) { if (args[i] == ' ' && !in_quote) break; if (equals == 0) { if (args[i] == '=') equals = i; } if (args[i] == '"') in_quote = !in_quote; } *param = args; if (!equals) *val = NULL; else { args[equals] = '\0'; *val = args + equals + 1; /* Don't include quotes in value. */ if (**val == '"') { (*val)++; if (args[i-1] == '"') args[i-1] = '\0'; } if (quoted && args[i-1] == '"') args[i-1] = '\0'; } if (args[i]) { args[i] = '\0'; next = args + i + 1; } else next = args + i; /* Chew up trailing spaces. */ while (*next == ' ') next++; return next; } /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ int parse_args(const char *name, char *args, struct kernel_param *params, unsigned num, int (*unknown)(char *param, char *val)) { char *param, *val; DEBUGP("Parsing ARGS: %s\n", args); /* Chew leading spaces */ while (*args == ' ') args++; while (*args) { int ret; args = next_arg(args, ¶m, &val); ret = parse_one(param, val, params, num, unknown); switch (ret) { case -ENOENT: printk(KERN_ERR "%s: Unknown parameter `%s'\n", name, param); return ret; case -ENOSPC: printk(KERN_ERR "%s: `%s' too large for parameter `%s'\n", name, val ?: "", param); return ret; case 0: break; default: printk(KERN_ERR "%s: `%s' invalid for parameter `%s'\n", name, val ?: "", param); return ret; } } /* All parsed OK. */ return 0; } /* Lazy bastard, eh? */ #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \ int param_set_##name(const char *val, struct kernel_param *kp) \ { \ char *endp; \ tmptype l; \ \ if (!val) return -EINVAL; \ l = strtolfn(val, &endp, 0); \ if (endp == val || ((type)l != l)) \ return -EINVAL; \ *((type *)kp->arg) = l; \ return 0; \ } \ int param_get_##name(char *buffer, struct kernel_param *kp) \ { \ return sprintf(buffer, format, *((type *)kp->arg)); \ } STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, simple_strtoul); STANDARD_PARAM_DEF(short, short, "%hi", long, simple_strtol); STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, simple_strtoul); STANDARD_PARAM_DEF(int, int, "%i", long, simple_strtol); STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, simple_strtoul); STANDARD_PARAM_DEF(long, long, "%li", long, simple_strtol); STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, simple_strtoul); int param_set_charp(const char *val, struct kernel_param *kp) { if (!val) { printk(KERN_ERR "%s: string parameter expected\n", kp->name); return -EINVAL; } if (strlen(val) > 1024) { printk(KERN_ERR "%s: string parameter too long\n", kp->name); return -ENOSPC; } *(char **)kp->arg = (char *)val; return 0; } int param_get_charp(char *buffer, struct kernel_param *kp) { return sprintf(buffer, "%s", *((char **)kp->arg)); } int param_set_bool(const char *val, struct kernel_param *kp) { /* No equals means "set"... */ if (!val) val = "1"; /* One of =[yYnN01] */ switch (val[0]) { case 'y': case 'Y': case '1': *(int *)kp->arg = 1; return 0; case 'n': case 'N': case '0': *(int *)kp->arg = 0; return 0; } return -EINVAL; } int param_get_bool(char *buffer, struct kernel_param *kp) { /* Y and N chosen as being relatively non-coder friendly */ return sprintf(buffer, "%c", (*(int *)kp->arg) ? 'Y' : 'N'); } int param_set_invbool(const char *val, struct kernel_param *kp) { int boolval, ret; struct kernel_param dummy = { .arg = &boolval }; ret = param_set_bool(val, &dummy); if (ret == 0) *(int *)kp->arg = !boolval; return ret; } int param_get_invbool(char *buffer, struct kernel_param *kp) { int val; struct kernel_param dummy = { .arg = &val }; val = !*(int *)kp->arg; return param_get_bool(buffer, &dummy); } /* We cheat here and temporarily mangle the string. */ int param_array(const char *name, const char *val, unsigned int min, unsigned int max, void *elem, int elemsize, int (*set)(const char *, struct kernel_param *kp), int *num) { int ret; struct kernel_param kp; char save; /* Get the name right for errors. */ kp.name = name; kp.arg = elem; /* No equals sign? */ if (!val) { printk(KERN_ERR "%s: expects arguments\n", name); return -EINVAL; } *num = 0; /* We expect a comma-separated list of values. */ do { int len; if (*num == max) { printk(KERN_ERR "%s: can only take %i arguments\n", name, max); return -EINVAL; } len = strcspn(val, ","); /* nul-terminate and parse */ save = val[len]; ((char *)val)[len] = '\0'; ret = set(val, &kp); if (ret != 0) return ret; kp.arg += elemsize; val += len+1; (*num)++; } while (save == ','); if (*num < min) { printk(KERN_ERR "%s: needs at least %i arguments\n", name, min); return -EINVAL; } return 0; } int param_array_set(const char *val, struct kernel_param *kp) { struct kparam_array *arr = kp->arg; unsigned int temp_num; return param_array(kp->name, val, 1, arr->max, arr->elem, arr->elemsize, arr->set, arr->num ?: &temp_num); } int param_array_get(char *buffer, struct kernel_param *kp) { int i, off, ret; struct kparam_array *arr = kp->arg; struct kernel_param p; p = *kp; for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { if (i) buffer[off++] = ','; p.arg = arr->elem + arr->elemsize * i; ret = arr->get(buffer + off, &p); if (ret < 0) return ret; off += ret; } buffer[off] = '\0'; return off; } int param_set_copystring(const char *val, struct kernel_param *kp) { struct kparam_string *kps = kp->arg; if (strlen(val)+1 > kps->maxlen) { printk(KERN_ERR "%s: string doesn't fit in %u chars.\n", kp->name, kps->maxlen-1); return -ENOSPC; } strcpy(kps->string, val); return 0; } int param_get_string(char *buffer, struct kernel_param *kp) { struct kparam_string *kps = kp->arg; return strlcpy(buffer, kps->string, kps->maxlen); } /* sysfs output in /sys/modules/XYZ/parameters/ */ extern struct kernel_param __start___param[], __stop___param[]; #define MAX_KBUILD_MODNAME KOBJ_NAME_LEN struct param_attribute { struct module_attribute mattr; struct kernel_param *param; }; struct module_param_attrs { struct attribute_group grp; struct param_attribute attrs[0]; }; #define to_param_attr(n) container_of(n, struct param_attribute, mattr); static ssize_t param_attr_show(struct module_attribute *mattr, struct module *mod, char *buf) { int count; struct param_attribute *attribute = to_param_attr(mattr); if (!attribute->param->get) return -EPERM; count = attribute->param->get(buf, attribute->param); if (count > 0) { strcat(buf, "\n"); ++count; } return count; } /* sysfs always hands a nul-terminated string in buf. We rely on that. */ static ssize_t param_attr_store(struct module_attribute *mattr, struct module *owner, const char *buf, size_t len) { int err; struct param_attribute *attribute = to_param_attr(mattr); if (!attribute->param->set) return -EPERM; err = attribute->param->set(buf, attribute->param); if (!err) return len; return err; } #ifdef CONFIG_MODULES #define __modinit #else #define __modinit __init #endif /* * param_sysfs_setup - setup sysfs support for one module or KBUILD_MODNAME * @mk: struct module_kobject (contains parent kobject) * @kparam: array of struct kernel_param, the actual parameter definitions * @num_params: number of entries in array * @name_skip: offset where the parameter name start in kparam[].name. Needed for built-in "modules" * * Create a kobject for a (per-module) group of parameters, and create files * in sysfs. A pointer to the param_kobject is returned on success, * NULL if there's no parameter to export, or other ERR_PTR(err). */ static __modinit struct module_param_attrs * param_sysfs_setup(struct module_kobject *mk, struct kernel_param *kparam, unsigned int num_params, unsigned int name_skip) { struct module_param_attrs *mp; unsigned int valid_attrs = 0; unsigned int i, size[2]; struct param_attribute *pattr; struct attribute **gattr; int err; for (i=0; i<num_params; i++) { if (kparam[i].perm) valid_attrs++; } if (!valid_attrs) return NULL; size[0] = ALIGN(sizeof(*mp) + valid_attrs * sizeof(mp->attrs[0]), sizeof(mp->grp.attrs[0])); size[1] = (valid_attrs + 1) * sizeof(mp->grp.attrs[0]); mp = kmalloc(size[0] + size[1], GFP_KERNEL); if (!mp) return ERR_PTR(-ENOMEM); mp->grp.name = "parameters"; mp->grp.attrs = (void *)mp + size[0]; pattr = &mp->attrs[0]; gattr = &mp->grp.attrs[0]; for (i = 0; i < num_params; i++) { struct kernel_param *kp = &kparam[i]; if (kp->perm) { pattr->param = kp; pattr->mattr.show = param_attr_show; pattr->mattr.store = param_attr_store; pattr->mattr.attr.name = (char *)&kp->name[name_skip]; pattr->mattr.attr.owner = mk->mod; pattr->mattr.attr.mode = kp->perm; *(gattr++) = &(pattr++)->mattr.attr; } } *gattr = NULL; if ((err = sysfs_create_group(&mk->kobj, &mp->grp))) { kfree(mp); return ERR_PTR(err); } return mp; } #ifdef CONFIG_MODULES /* * module_param_sysfs_setup - setup sysfs support for one module * @mod: module * @kparam: module parameters (array) * @num_params: number of module parameters * * Adds sysfs entries for module parameters, and creates a link from * /sys/module/[mod->name]/parameters to /sys/parameters/[mod->name]/ */ int module_param_sysfs_setup(struct module *mod, struct kernel_param *kparam, unsigned int num_params) { struct module_param_attrs *mp; mp = param_sysfs_setup(&mod->mkobj, kparam, num_params, 0); if (IS_ERR(mp)) return PTR_ERR(mp); mod->param_attrs = mp; return 0; } /* * module_param_sysfs_remove - remove sysfs support for one module * @mod: module * * Remove sysfs entries for module parameters and the corresponding * kobject. */ void module_param_sysfs_remove(struct module *mod) { if (mod->param_attrs) { sysfs_remove_group(&mod->mkobj.kobj, &mod->param_attrs->grp); /* We are positive that no one is using any param * attrs at this point. Deallocate immediately. */ kfree(mod->param_attrs); mod->param_attrs = NULL; } } #endif /* * kernel_param_sysfs_setup - wrapper for built-in params support */ static void __init kernel_param_sysfs_setup(const char *name, struct kernel_param *kparam, unsigned int num_params, unsigned int name_skip) { struct module_kobject *mk; mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); BUG_ON(!mk); mk->mod = THIS_MODULE; kobj_set_kset_s(mk, module_subsys); kobject_set_name(&mk->kobj, name); kobject_register(&mk->kobj); /* no need to keep the kobject if no parameter is exported */ if (!param_sysfs_setup(mk, kparam, num_params, name_skip)) { kobject_unregister(&mk->kobj); kfree(mk); } } /* * param_sysfs_builtin - add contents in /sys/parameters for built-in modules * * Add module_parameters to sysfs for "modules" built into the kernel. * * The "module" name (KBUILD_MODNAME) is stored before a dot, the * "parameter" name is stored behind a dot in kernel_param->name. So, * extract the "module" name for all built-in kernel_param-eters, * and for all who have the same, call kernel_param_sysfs_setup. */ static void __init param_sysfs_builtin(void) { struct kernel_param *kp, *kp_begin = NULL; unsigned int i, name_len, count = 0; char modname[MAX_KBUILD_MODNAME + 1] = ""; for (i=0; i < __stop___param - __start___param; i++) { char *dot; kp = &__start___param[i]; /* We do not handle args without periods. */ dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME); if (!dot) { DEBUGP("couldn't find period in %s\n", kp->name); continue; } name_len = dot - kp->name; /* new kbuild_modname? */ if (strlen(modname) != name_len || strncmp(modname, kp->name, name_len) != 0) { /* add a new kobject for previous kernel_params. */ if (count) kernel_param_sysfs_setup(modname, kp_begin, count, strlen(modname)+1); strncpy(modname, kp->name, name_len); modname[name_len] = '\0'; count = 0; kp_begin = kp; } count++; } /* last kernel_params need to be registered as well */ if (count) kernel_param_sysfs_setup(modname, kp_begin, count, strlen(modname)+1); } /* module-related sysfs stuff */ #ifdef CONFIG_MODULES #define to_module_attr(n) container_of(n, struct module_attribute, attr); #define to_module_kobject(n) container_of(n, struct module_kobject, kobj); static ssize_t module_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { struct module_attribute *attribute; struct module_kobject *mk; int ret; attribute = to_module_attr(attr); mk = to_module_kobject(kobj); if (!attribute->show) return -EIO; if (!try_module_get(mk->mod)) return -ENODEV; ret = attribute->show(attribute, mk->mod, buf); module_put(mk->mod); return ret; } static ssize_t module_attr_store(struct kobject *kobj, struct attribute *attr, const char *buf, size_t len) { struct module_attribute *attribute; struct module_kobject *mk; int ret; attribute = to_module_attr(attr); mk = to_module_kobject(kobj); if (!attribute->store) return -EIO; if (!try_module_get(mk->mod)) return -ENODEV; ret = attribute->store(attribute, mk->mod, buf, len); module_put(mk->mod); return ret; } static struct sysfs_ops module_sysfs_ops = { .show = module_attr_show, .store = module_attr_store, }; #else static struct sysfs_ops module_sysfs_ops = { .show = NULL, .store = NULL, }; #endif static struct kobj_type module_ktype = { .sysfs_ops = &module_sysfs_ops, }; decl_subsys(module, &module_ktype, NULL); /* * param_sysfs_init - wrapper for built-in params support */ static int __init param_sysfs_init(void) { subsystem_register(&module_subsys); param_sysfs_builtin(); return 0; } __initcall(param_sysfs_init); EXPORT_SYMBOL(param_set_byte); EXPORT_SYMBOL(param_get_byte); EXPORT_SYMBOL(param_set_short); EXPORT_SYMBOL(param_get_short); EXPORT_SYMBOL(param_set_ushort); EXPORT_SYMBOL(param_get_ushort); EXPORT_SYMBOL(param_set_int); EXPORT_SYMBOL(param_get_int); EXPORT_SYMBOL(param_set_uint); EXPORT_SYMBOL(param_get_uint); EXPORT_SYMBOL(param_set_long); EXPORT_SYMBOL(param_get_long); EXPORT_SYMBOL(param_set_ulong); EXPORT_SYMBOL(param_get_ulong); EXPORT_SYMBOL(param_set_charp); EXPORT_SYMBOL(param_get_charp); EXPORT_SYMBOL(param_set_bool); EXPORT_SYMBOL(param_get_bool); EXPORT_SYMBOL(param_set_invbool); EXPORT_SYMBOL(param_get_invbool); EXPORT_SYMBOL(param_array_set); EXPORT_SYMBOL(param_array_get); EXPORT_SYMBOL(param_set_copystring); EXPORT_SYMBOL(param_get_string);