1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Export SMBIOS/DMI info via sysfs to userspace
4 *
5 * Copyright 2007, Lennart Poettering
6 */
7
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/dmi.h>
12 #include <linux/device.h>
13 #include <linux/slab.h>
14
15 struct dmi_device_attribute{
16 struct device_attribute dev_attr;
17 int field;
18 };
19 #define to_dmi_dev_attr(_dev_attr) \
20 container_of(_dev_attr, struct dmi_device_attribute, dev_attr)
21
sys_dmi_field_show(struct device * dev,struct device_attribute * attr,char * page)22 static ssize_t sys_dmi_field_show(struct device *dev,
23 struct device_attribute *attr,
24 char *page)
25 {
26 int field = to_dmi_dev_attr(attr)->field;
27 ssize_t len;
28 len = scnprintf(page, PAGE_SIZE, "%s\n", dmi_get_system_info(field));
29 page[len-1] = '\n';
30 return len;
31 }
32
33 #define DMI_ATTR(_name, _mode, _show, _field) \
34 { .dev_attr = __ATTR(_name, _mode, _show, NULL), \
35 .field = _field }
36
37 #define DEFINE_DMI_ATTR_WITH_SHOW(_name, _mode, _field) \
38 static struct dmi_device_attribute sys_dmi_##_name##_attr = \
39 DMI_ATTR(_name, _mode, sys_dmi_field_show, _field);
40
41 DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor, 0444, DMI_BIOS_VENDOR);
42 DEFINE_DMI_ATTR_WITH_SHOW(bios_version, 0444, DMI_BIOS_VERSION);
43 DEFINE_DMI_ATTR_WITH_SHOW(bios_date, 0444, DMI_BIOS_DATE);
44 DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor, 0444, DMI_SYS_VENDOR);
45 DEFINE_DMI_ATTR_WITH_SHOW(product_name, 0444, DMI_PRODUCT_NAME);
46 DEFINE_DMI_ATTR_WITH_SHOW(product_version, 0444, DMI_PRODUCT_VERSION);
47 DEFINE_DMI_ATTR_WITH_SHOW(product_serial, 0400, DMI_PRODUCT_SERIAL);
48 DEFINE_DMI_ATTR_WITH_SHOW(product_uuid, 0400, DMI_PRODUCT_UUID);
49 DEFINE_DMI_ATTR_WITH_SHOW(product_sku, 0444, DMI_PRODUCT_SKU);
50 DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0444, DMI_PRODUCT_FAMILY);
51 DEFINE_DMI_ATTR_WITH_SHOW(board_vendor, 0444, DMI_BOARD_VENDOR);
52 DEFINE_DMI_ATTR_WITH_SHOW(board_name, 0444, DMI_BOARD_NAME);
53 DEFINE_DMI_ATTR_WITH_SHOW(board_version, 0444, DMI_BOARD_VERSION);
54 DEFINE_DMI_ATTR_WITH_SHOW(board_serial, 0400, DMI_BOARD_SERIAL);
55 DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag, 0444, DMI_BOARD_ASSET_TAG);
56 DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor, 0444, DMI_CHASSIS_VENDOR);
57 DEFINE_DMI_ATTR_WITH_SHOW(chassis_type, 0444, DMI_CHASSIS_TYPE);
58 DEFINE_DMI_ATTR_WITH_SHOW(chassis_version, 0444, DMI_CHASSIS_VERSION);
59 DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial, 0400, DMI_CHASSIS_SERIAL);
60 DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag, 0444, DMI_CHASSIS_ASSET_TAG);
61
ascii_filter(char * d,const char * s)62 static void ascii_filter(char *d, const char *s)
63 {
64 /* Filter out characters we don't want to see in the modalias string */
65 for (; *s; s++)
66 if (*s > ' ' && *s < 127 && *s != ':')
67 *(d++) = *s;
68
69 *d = 0;
70 }
71
get_modalias(char * buffer,size_t buffer_size)72 static ssize_t get_modalias(char *buffer, size_t buffer_size)
73 {
74 static const struct mafield {
75 const char *prefix;
76 int field;
77 } fields[] = {
78 { "bvn", DMI_BIOS_VENDOR },
79 { "bvr", DMI_BIOS_VERSION },
80 { "bd", DMI_BIOS_DATE },
81 { "svn", DMI_SYS_VENDOR },
82 { "pn", DMI_PRODUCT_NAME },
83 { "pvr", DMI_PRODUCT_VERSION },
84 { "rvn", DMI_BOARD_VENDOR },
85 { "rn", DMI_BOARD_NAME },
86 { "rvr", DMI_BOARD_VERSION },
87 { "cvn", DMI_CHASSIS_VENDOR },
88 { "ct", DMI_CHASSIS_TYPE },
89 { "cvr", DMI_CHASSIS_VERSION },
90 { NULL, DMI_NONE }
91 };
92
93 ssize_t l, left;
94 char *p;
95 const struct mafield *f;
96
97 strcpy(buffer, "dmi");
98 p = buffer + 3; left = buffer_size - 4;
99
100 for (f = fields; f->prefix && left > 0; f++) {
101 const char *c;
102 char *t;
103
104 c = dmi_get_system_info(f->field);
105 if (!c)
106 continue;
107
108 t = kmalloc(strlen(c) + 1, GFP_KERNEL);
109 if (!t)
110 break;
111 ascii_filter(t, c);
112 l = scnprintf(p, left, ":%s%s", f->prefix, t);
113 kfree(t);
114
115 p += l;
116 left -= l;
117 }
118
119 p[0] = ':';
120 p[1] = 0;
121
122 return p - buffer + 1;
123 }
124
sys_dmi_modalias_show(struct device * dev,struct device_attribute * attr,char * page)125 static ssize_t sys_dmi_modalias_show(struct device *dev,
126 struct device_attribute *attr, char *page)
127 {
128 ssize_t r;
129 r = get_modalias(page, PAGE_SIZE-1);
130 page[r] = '\n';
131 page[r+1] = 0;
132 return r+1;
133 }
134
135 static struct device_attribute sys_dmi_modalias_attr =
136 __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL);
137
138 static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2];
139
140 static struct attribute_group sys_dmi_attribute_group = {
141 .attrs = sys_dmi_attributes,
142 };
143
144 static const struct attribute_group* sys_dmi_attribute_groups[] = {
145 &sys_dmi_attribute_group,
146 NULL
147 };
148
dmi_dev_uevent(struct device * dev,struct kobj_uevent_env * env)149 static int dmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
150 {
151 ssize_t len;
152
153 if (add_uevent_var(env, "MODALIAS="))
154 return -ENOMEM;
155 len = get_modalias(&env->buf[env->buflen - 1],
156 sizeof(env->buf) - env->buflen);
157 if (len >= (sizeof(env->buf) - env->buflen))
158 return -ENOMEM;
159 env->buflen += len;
160 return 0;
161 }
162
163 static struct class dmi_class = {
164 .name = "dmi",
165 .dev_release = (void(*)(struct device *)) kfree,
166 .dev_uevent = dmi_dev_uevent,
167 };
168
169 static struct device *dmi_dev;
170
171 /* Initialization */
172
173 #define ADD_DMI_ATTR(_name, _field) \
174 if (dmi_get_system_info(_field)) \
175 sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr;
176
177 /* In a separate function to keep gcc 3.2 happy - do NOT merge this in
178 dmi_id_init! */
dmi_id_init_attr_table(void)179 static void __init dmi_id_init_attr_table(void)
180 {
181 int i;
182
183 /* Not necessarily all DMI fields are available on all
184 * systems, hence let's built an attribute table of just
185 * what's available */
186 i = 0;
187 ADD_DMI_ATTR(bios_vendor, DMI_BIOS_VENDOR);
188 ADD_DMI_ATTR(bios_version, DMI_BIOS_VERSION);
189 ADD_DMI_ATTR(bios_date, DMI_BIOS_DATE);
190 ADD_DMI_ATTR(sys_vendor, DMI_SYS_VENDOR);
191 ADD_DMI_ATTR(product_name, DMI_PRODUCT_NAME);
192 ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION);
193 ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL);
194 ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID);
195 ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY);
196 ADD_DMI_ATTR(product_sku, DMI_PRODUCT_SKU);
197 ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR);
198 ADD_DMI_ATTR(board_name, DMI_BOARD_NAME);
199 ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION);
200 ADD_DMI_ATTR(board_serial, DMI_BOARD_SERIAL);
201 ADD_DMI_ATTR(board_asset_tag, DMI_BOARD_ASSET_TAG);
202 ADD_DMI_ATTR(chassis_vendor, DMI_CHASSIS_VENDOR);
203 ADD_DMI_ATTR(chassis_type, DMI_CHASSIS_TYPE);
204 ADD_DMI_ATTR(chassis_version, DMI_CHASSIS_VERSION);
205 ADD_DMI_ATTR(chassis_serial, DMI_CHASSIS_SERIAL);
206 ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG);
207 sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr;
208 }
209
dmi_id_init(void)210 static int __init dmi_id_init(void)
211 {
212 int ret;
213
214 if (!dmi_available)
215 return -ENODEV;
216
217 dmi_id_init_attr_table();
218
219 ret = class_register(&dmi_class);
220 if (ret)
221 return ret;
222
223 dmi_dev = kzalloc(sizeof(*dmi_dev), GFP_KERNEL);
224 if (!dmi_dev) {
225 ret = -ENOMEM;
226 goto fail_class_unregister;
227 }
228
229 dmi_dev->class = &dmi_class;
230 dev_set_name(dmi_dev, "id");
231 dmi_dev->groups = sys_dmi_attribute_groups;
232
233 ret = device_register(dmi_dev);
234 if (ret)
235 goto fail_put_dmi_dev;
236
237 return 0;
238
239 fail_put_dmi_dev:
240 put_device(dmi_dev);
241
242 fail_class_unregister:
243 class_unregister(&dmi_class);
244
245 return ret;
246 }
247
248 arch_initcall(dmi_id_init);
249