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
15struct 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
22static 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(buf: page, PAGE_SIZE, fmt: "%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) \
38static struct dmi_device_attribute sys_dmi_##_name##_attr = \
39 DMI_ATTR(_name, _mode, sys_dmi_field_show, _field);
40
41DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor, 0444, DMI_BIOS_VENDOR);
42DEFINE_DMI_ATTR_WITH_SHOW(bios_version, 0444, DMI_BIOS_VERSION);
43DEFINE_DMI_ATTR_WITH_SHOW(bios_date, 0444, DMI_BIOS_DATE);
44DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor, 0444, DMI_SYS_VENDOR);
45DEFINE_DMI_ATTR_WITH_SHOW(bios_release, 0444, DMI_BIOS_RELEASE);
46DEFINE_DMI_ATTR_WITH_SHOW(ec_firmware_release, 0444, DMI_EC_FIRMWARE_RELEASE);
47DEFINE_DMI_ATTR_WITH_SHOW(product_name, 0444, DMI_PRODUCT_NAME);
48DEFINE_DMI_ATTR_WITH_SHOW(product_version, 0444, DMI_PRODUCT_VERSION);
49DEFINE_DMI_ATTR_WITH_SHOW(product_serial, 0400, DMI_PRODUCT_SERIAL);
50DEFINE_DMI_ATTR_WITH_SHOW(product_uuid, 0400, DMI_PRODUCT_UUID);
51DEFINE_DMI_ATTR_WITH_SHOW(product_sku, 0444, DMI_PRODUCT_SKU);
52DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0444, DMI_PRODUCT_FAMILY);
53DEFINE_DMI_ATTR_WITH_SHOW(board_vendor, 0444, DMI_BOARD_VENDOR);
54DEFINE_DMI_ATTR_WITH_SHOW(board_name, 0444, DMI_BOARD_NAME);
55DEFINE_DMI_ATTR_WITH_SHOW(board_version, 0444, DMI_BOARD_VERSION);
56DEFINE_DMI_ATTR_WITH_SHOW(board_serial, 0400, DMI_BOARD_SERIAL);
57DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag, 0444, DMI_BOARD_ASSET_TAG);
58DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor, 0444, DMI_CHASSIS_VENDOR);
59DEFINE_DMI_ATTR_WITH_SHOW(chassis_type, 0444, DMI_CHASSIS_TYPE);
60DEFINE_DMI_ATTR_WITH_SHOW(chassis_version, 0444, DMI_CHASSIS_VERSION);
61DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial, 0400, DMI_CHASSIS_SERIAL);
62DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag, 0444, DMI_CHASSIS_ASSET_TAG);
63
64static 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
74static ssize_t get_modalias(char *buffer, size_t buffer_size)
75{
76 /*
77 * Note new fields need to be added at the end to keep compatibility
78 * with udev's hwdb which does matches on "`cat dmi/id/modalias`*".
79 */
80 static const struct mafield {
81 const char *prefix;
82 int field;
83 } fields[] = {
84 { "bvn", DMI_BIOS_VENDOR },
85 { .prefix: "bvr", .field: DMI_BIOS_VERSION },
86 { .prefix: "bd", .field: DMI_BIOS_DATE },
87 { .prefix: "br", .field: DMI_BIOS_RELEASE },
88 { .prefix: "efr", .field: DMI_EC_FIRMWARE_RELEASE },
89 { .prefix: "svn", .field: DMI_SYS_VENDOR },
90 { .prefix: "pn", .field: DMI_PRODUCT_NAME },
91 { .prefix: "pvr", .field: DMI_PRODUCT_VERSION },
92 { .prefix: "rvn", .field: DMI_BOARD_VENDOR },
93 { .prefix: "rn", .field: DMI_BOARD_NAME },
94 { .prefix: "rvr", .field: DMI_BOARD_VERSION },
95 { .prefix: "cvn", .field: DMI_CHASSIS_VENDOR },
96 { .prefix: "ct", .field: DMI_CHASSIS_TYPE },
97 { .prefix: "cvr", .field: DMI_CHASSIS_VERSION },
98 { .prefix: "sku", .field: DMI_PRODUCT_SKU },
99 { NULL, .field: DMI_NONE }
100 };
101
102 ssize_t l, left;
103 char *p;
104 const struct mafield *f;
105
106 strcpy(buffer, "dmi");
107 p = buffer + 3; left = buffer_size - 4;
108
109 for (f = fields; f->prefix && left > 0; f++) {
110 const char *c;
111 char *t;
112
113 c = dmi_get_system_info(field: f->field);
114 if (!c)
115 continue;
116
117 t = kmalloc(strlen(c) + 1, GFP_KERNEL);
118 if (!t)
119 break;
120 ascii_filter(d: t, s: c);
121 l = scnprintf(buf: p, size: left, fmt: ":%s%s", f->prefix, t);
122 kfree(objp: t);
123
124 p += l;
125 left -= l;
126 }
127
128 p[0] = ':';
129 p[1] = 0;
130
131 return p - buffer + 1;
132}
133
134static ssize_t sys_dmi_modalias_show(struct device *dev,
135 struct device_attribute *attr, char *page)
136{
137 ssize_t r;
138 r = get_modalias(buffer: page, PAGE_SIZE-1);
139 page[r] = '\n';
140 page[r+1] = 0;
141 return r+1;
142}
143
144static struct device_attribute sys_dmi_modalias_attr =
145 __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL);
146
147static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2];
148
149static struct attribute_group sys_dmi_attribute_group = {
150 .attrs = sys_dmi_attributes,
151};
152
153static const struct attribute_group* sys_dmi_attribute_groups[] = {
154 &sys_dmi_attribute_group,
155 NULL
156};
157
158static int dmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env)
159{
160 ssize_t len;
161
162 if (add_uevent_var(env, format: "MODALIAS="))
163 return -ENOMEM;
164 len = get_modalias(buffer: &env->buf[env->buflen - 1],
165 buffer_size: sizeof(env->buf) - env->buflen);
166 if (len >= (sizeof(env->buf) - env->buflen))
167 return -ENOMEM;
168 env->buflen += len;
169 return 0;
170}
171
172static void dmi_dev_release(struct device *dev)
173{
174 kfree(objp: dev);
175}
176
177static struct class dmi_class = {
178 .name = "dmi",
179 .dev_release = dmi_dev_release,
180 .dev_uevent = dmi_dev_uevent,
181};
182
183static struct device *dmi_dev;
184
185/* Initialization */
186
187#define ADD_DMI_ATTR(_name, _field) \
188 if (dmi_get_system_info(_field)) \
189 sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr;
190
191/* In a separate function to keep gcc 3.2 happy - do NOT merge this in
192 dmi_id_init! */
193static void __init dmi_id_init_attr_table(void)
194{
195 int i;
196
197 /* Not necessarily all DMI fields are available on all
198 * systems, hence let's built an attribute table of just
199 * what's available */
200 i = 0;
201 ADD_DMI_ATTR(bios_vendor, DMI_BIOS_VENDOR);
202 ADD_DMI_ATTR(bios_version, DMI_BIOS_VERSION);
203 ADD_DMI_ATTR(bios_date, DMI_BIOS_DATE);
204 ADD_DMI_ATTR(bios_release, DMI_BIOS_RELEASE);
205 ADD_DMI_ATTR(ec_firmware_release, DMI_EC_FIRMWARE_RELEASE);
206 ADD_DMI_ATTR(sys_vendor, DMI_SYS_VENDOR);
207 ADD_DMI_ATTR(product_name, DMI_PRODUCT_NAME);
208 ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION);
209 ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL);
210 ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID);
211 ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY);
212 ADD_DMI_ATTR(product_sku, DMI_PRODUCT_SKU);
213 ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR);
214 ADD_DMI_ATTR(board_name, DMI_BOARD_NAME);
215 ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION);
216 ADD_DMI_ATTR(board_serial, DMI_BOARD_SERIAL);
217 ADD_DMI_ATTR(board_asset_tag, DMI_BOARD_ASSET_TAG);
218 ADD_DMI_ATTR(chassis_vendor, DMI_CHASSIS_VENDOR);
219 ADD_DMI_ATTR(chassis_type, DMI_CHASSIS_TYPE);
220 ADD_DMI_ATTR(chassis_version, DMI_CHASSIS_VERSION);
221 ADD_DMI_ATTR(chassis_serial, DMI_CHASSIS_SERIAL);
222 ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG);
223 sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr;
224}
225
226static int __init dmi_id_init(void)
227{
228 int ret;
229
230 if (!dmi_available)
231 return -ENODEV;
232
233 dmi_id_init_attr_table();
234
235 ret = class_register(class: &dmi_class);
236 if (ret)
237 return ret;
238
239 dmi_dev = kzalloc(sizeof(*dmi_dev), GFP_KERNEL);
240 if (!dmi_dev) {
241 ret = -ENOMEM;
242 goto fail_class_unregister;
243 }
244
245 dmi_dev->class = &dmi_class;
246 dev_set_name(dev: dmi_dev, name: "id");
247 dmi_dev->groups = sys_dmi_attribute_groups;
248
249 ret = device_register(dev: dmi_dev);
250 if (ret)
251 goto fail_put_dmi_dev;
252
253 return 0;
254
255fail_put_dmi_dev:
256 put_device(dev: dmi_dev);
257
258fail_class_unregister:
259 class_unregister(class: &dmi_class);
260
261 return ret;
262}
263
264arch_initcall(dmi_id_init);
265