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(bios_release, 0444, DMI_BIOS_RELEASE);
46 DEFINE_DMI_ATTR_WITH_SHOW(ec_firmware_release, 0444, DMI_EC_FIRMWARE_RELEASE);
47 DEFINE_DMI_ATTR_WITH_SHOW(product_name, 0444, DMI_PRODUCT_NAME);
48 DEFINE_DMI_ATTR_WITH_SHOW(product_version, 0444, DMI_PRODUCT_VERSION);
49 DEFINE_DMI_ATTR_WITH_SHOW(product_serial, 0400, DMI_PRODUCT_SERIAL);
50 DEFINE_DMI_ATTR_WITH_SHOW(product_uuid, 0400, DMI_PRODUCT_UUID);
51 DEFINE_DMI_ATTR_WITH_SHOW(product_sku, 0444, DMI_PRODUCT_SKU);
52 DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0444, DMI_PRODUCT_FAMILY);
53 DEFINE_DMI_ATTR_WITH_SHOW(board_vendor, 0444, DMI_BOARD_VENDOR);
54 DEFINE_DMI_ATTR_WITH_SHOW(board_name, 0444, DMI_BOARD_NAME);
55 DEFINE_DMI_ATTR_WITH_SHOW(board_version, 0444, DMI_BOARD_VERSION);
56 DEFINE_DMI_ATTR_WITH_SHOW(board_serial, 0400, DMI_BOARD_SERIAL);
57 DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag, 0444, DMI_BOARD_ASSET_TAG);
58 DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor, 0444, DMI_CHASSIS_VENDOR);
59 DEFINE_DMI_ATTR_WITH_SHOW(chassis_type, 0444, DMI_CHASSIS_TYPE);
60 DEFINE_DMI_ATTR_WITH_SHOW(chassis_version, 0444, DMI_CHASSIS_VERSION);
61 DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial, 0400, DMI_CHASSIS_SERIAL);
62 DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag, 0444, DMI_CHASSIS_ASSET_TAG);
63
ascii_filter(char * d,const char * s)64 static void ascii_filter(char *d, const char *s)
65 {
66 /* Filter out characters we don't want to see in the modalias string */
67 for (; *s; s++)
68 if (*s > ' ' && *s < 127 && *s != ':')
69 *(d++) = *s;
70
71 *d = 0;
72 }
73
get_modalias(char * buffer,size_t buffer_size)74 static ssize_t get_modalias(char *buffer, size_t buffer_size)
75 {
76 static const struct mafield {
77 const char *prefix;
78 int field;
79 } fields[] = {
80 { "bvn", DMI_BIOS_VENDOR },
81 { "bvr", DMI_BIOS_VERSION },
82 { "bd", DMI_BIOS_DATE },
83 { "br", DMI_BIOS_RELEASE },
84 { "efr", DMI_EC_FIRMWARE_RELEASE },
85 { "svn", DMI_SYS_VENDOR },
86 { "pn", DMI_PRODUCT_NAME },
87 { "pvr", DMI_PRODUCT_VERSION },
88 { "sku", DMI_PRODUCT_SKU },
89 { "rvn", DMI_BOARD_VENDOR },
90 { "rn", DMI_BOARD_NAME },
91 { "rvr", DMI_BOARD_VERSION },
92 { "cvn", DMI_CHASSIS_VENDOR },
93 { "ct", DMI_CHASSIS_TYPE },
94 { "cvr", DMI_CHASSIS_VERSION },
95 { NULL, DMI_NONE }
96 };
97
98 ssize_t l, left;
99 char *p;
100 const struct mafield *f;
101
102 strcpy(buffer, "dmi");
103 p = buffer + 3; left = buffer_size - 4;
104
105 for (f = fields; f->prefix && left > 0; f++) {
106 const char *c;
107 char *t;
108
109 c = dmi_get_system_info(f->field);
110 if (!c)
111 continue;
112
113 t = kmalloc(strlen(c) + 1, GFP_KERNEL);
114 if (!t)
115 break;
116 ascii_filter(t, c);
117 l = scnprintf(p, left, ":%s%s", f->prefix, t);
118 kfree(t);
119
120 p += l;
121 left -= l;
122 }
123
124 p[0] = ':';
125 p[1] = 0;
126
127 return p - buffer + 1;
128 }
129
sys_dmi_modalias_show(struct device * dev,struct device_attribute * attr,char * page)130 static ssize_t sys_dmi_modalias_show(struct device *dev,
131 struct device_attribute *attr, char *page)
132 {
133 ssize_t r;
134 r = get_modalias(page, PAGE_SIZE-1);
135 page[r] = '\n';
136 page[r+1] = 0;
137 return r+1;
138 }
139
140 static struct device_attribute sys_dmi_modalias_attr =
141 __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL);
142
143 static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2];
144
145 static struct attribute_group sys_dmi_attribute_group = {
146 .attrs = sys_dmi_attributes,
147 };
148
149 static const struct attribute_group* sys_dmi_attribute_groups[] = {
150 &sys_dmi_attribute_group,
151 NULL
152 };
153
dmi_dev_uevent(struct device * dev,struct kobj_uevent_env * env)154 static int dmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
155 {
156 ssize_t len;
157
158 if (add_uevent_var(env, "MODALIAS="))
159 return -ENOMEM;
160 len = get_modalias(&env->buf[env->buflen - 1],
161 sizeof(env->buf) - env->buflen);
162 if (len >= (sizeof(env->buf) - env->buflen))
163 return -ENOMEM;
164 env->buflen += len;
165 return 0;
166 }
167
168 static struct class dmi_class = {
169 .name = "dmi",
170 .dev_release = (void(*)(struct device *)) kfree,
171 .dev_uevent = dmi_dev_uevent,
172 };
173
174 static struct device *dmi_dev;
175
176 /* Initialization */
177
178 #define ADD_DMI_ATTR(_name, _field) \
179 if (dmi_get_system_info(_field)) \
180 sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr;
181
182 /* In a separate function to keep gcc 3.2 happy - do NOT merge this in
183 dmi_id_init! */
dmi_id_init_attr_table(void)184 static void __init dmi_id_init_attr_table(void)
185 {
186 int i;
187
188 /* Not necessarily all DMI fields are available on all
189 * systems, hence let's built an attribute table of just
190 * what's available */
191 i = 0;
192 ADD_DMI_ATTR(bios_vendor, DMI_BIOS_VENDOR);
193 ADD_DMI_ATTR(bios_version, DMI_BIOS_VERSION);
194 ADD_DMI_ATTR(bios_date, DMI_BIOS_DATE);
195 ADD_DMI_ATTR(bios_release, DMI_BIOS_RELEASE);
196 ADD_DMI_ATTR(ec_firmware_release, DMI_EC_FIRMWARE_RELEASE);
197 ADD_DMI_ATTR(sys_vendor, DMI_SYS_VENDOR);
198 ADD_DMI_ATTR(product_name, DMI_PRODUCT_NAME);
199 ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION);
200 ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL);
201 ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID);
202 ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY);
203 ADD_DMI_ATTR(product_sku, DMI_PRODUCT_SKU);
204 ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR);
205 ADD_DMI_ATTR(board_name, DMI_BOARD_NAME);
206 ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION);
207 ADD_DMI_ATTR(board_serial, DMI_BOARD_SERIAL);
208 ADD_DMI_ATTR(board_asset_tag, DMI_BOARD_ASSET_TAG);
209 ADD_DMI_ATTR(chassis_vendor, DMI_CHASSIS_VENDOR);
210 ADD_DMI_ATTR(chassis_type, DMI_CHASSIS_TYPE);
211 ADD_DMI_ATTR(chassis_version, DMI_CHASSIS_VERSION);
212 ADD_DMI_ATTR(chassis_serial, DMI_CHASSIS_SERIAL);
213 ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG);
214 sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr;
215 }
216
dmi_id_init(void)217 static int __init dmi_id_init(void)
218 {
219 int ret;
220
221 if (!dmi_available)
222 return -ENODEV;
223
224 dmi_id_init_attr_table();
225
226 ret = class_register(&dmi_class);
227 if (ret)
228 return ret;
229
230 dmi_dev = kzalloc(sizeof(*dmi_dev), GFP_KERNEL);
231 if (!dmi_dev) {
232 ret = -ENOMEM;
233 goto fail_class_unregister;
234 }
235
236 dmi_dev->class = &dmi_class;
237 dev_set_name(dmi_dev, "id");
238 dmi_dev->groups = sys_dmi_attribute_groups;
239
240 ret = device_register(dmi_dev);
241 if (ret)
242 goto fail_put_dmi_dev;
243
244 return 0;
245
246 fail_put_dmi_dev:
247 put_device(dmi_dev);
248
249 fail_class_unregister:
250 class_unregister(&dmi_class);
251
252 return ret;
253 }
254
255 arch_initcall(dmi_id_init);
256