dmi-id.c

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/*
 * Export SMBIOS/DMI info via sysfs to userspace
 *
 * Copyright 2007, Lennart Poettering
 *
 * Licensed under GPLv2
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/device.h>
#include <linux/slab.h>

struct dmi_device_attribute{
    struct device_attribute dev_attr;
    int field;
};
#define to_dmi_dev_attr(_dev_attr) \
    container_of(_dev_attr, struct dmi_device_attribute, dev_attr)

static ssize_t sys_dmi_field_show(struct device *dev,
                  struct device_attribute *attr,
                  char *page)
{
    int field = to_dmi_dev_attr(attr)->field;
    ssize_t len;
    len = scnprintf(page, PAGE_SIZE, "%s\n", dmi_get_system_info(field));
    page[len-1] = '\n';
    return len;
}

#define DMI_ATTR(_name, _mode, _show, _field)           \
    { .dev_attr = __ATTR(_name, _mode, _show, NULL),    \
      .field = _field }

#define DEFINE_DMI_ATTR_WITH_SHOW(_name, _mode, _field)     \
static struct dmi_device_attribute sys_dmi_##_name##_attr = \
    DMI_ATTR(_name, _mode, sys_dmi_field_show, _field);

DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor,      0444, DMI_BIOS_VENDOR);
DEFINE_DMI_ATTR_WITH_SHOW(bios_version,     0444, DMI_BIOS_VERSION);
DEFINE_DMI_ATTR_WITH_SHOW(bios_date,        0444, DMI_BIOS_DATE);
DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor,       0444, DMI_SYS_VENDOR);
DEFINE_DMI_ATTR_WITH_SHOW(product_name,     0444, DMI_PRODUCT_NAME);
DEFINE_DMI_ATTR_WITH_SHOW(product_version,  0444, DMI_PRODUCT_VERSION);
DEFINE_DMI_ATTR_WITH_SHOW(product_serial,   0400, DMI_PRODUCT_SERIAL);
DEFINE_DMI_ATTR_WITH_SHOW(product_uuid,     0400, DMI_PRODUCT_UUID);
DEFINE_DMI_ATTR_WITH_SHOW(board_vendor,     0444, DMI_BOARD_VENDOR);
DEFINE_DMI_ATTR_WITH_SHOW(board_name,       0444, DMI_BOARD_NAME);
DEFINE_DMI_ATTR_WITH_SHOW(board_version,    0444, DMI_BOARD_VERSION);
DEFINE_DMI_ATTR_WITH_SHOW(board_serial,     0400, DMI_BOARD_SERIAL);
DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag,  0444, DMI_BOARD_ASSET_TAG);
DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor,   0444, DMI_CHASSIS_VENDOR);
DEFINE_DMI_ATTR_WITH_SHOW(chassis_type,     0444, DMI_CHASSIS_TYPE);
DEFINE_DMI_ATTR_WITH_SHOW(chassis_version,  0444, DMI_CHASSIS_VERSION);
DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial,   0400, DMI_CHASSIS_SERIAL);
DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag,    0444, DMI_CHASSIS_ASSET_TAG);

static void ascii_filter(char *d, const char *s)
{
    /* Filter out characters we don't want to see in the modalias string */
    for (; *s; s++)
        if (*s > ' ' && *s < 127 && *s != ':')
            *(d++) = *s;

    *d = 0;
}

static ssize_t get_modalias(char *buffer, size_t buffer_size)
{
    static const struct mafield {
        const char *prefix;
        int field;
    } fields[] = {
        { "bvn", DMI_BIOS_VENDOR },
        { "bvr", DMI_BIOS_VERSION },
        { "bd",  DMI_BIOS_DATE },
        { "svn", DMI_SYS_VENDOR },
        { "pn",  DMI_PRODUCT_NAME },
        { "pvr", DMI_PRODUCT_VERSION },
        { "rvn", DMI_BOARD_VENDOR },
        { "rn",  DMI_BOARD_NAME },
        { "rvr", DMI_BOARD_VERSION },
        { "cvn", DMI_CHASSIS_VENDOR },
        { "ct",  DMI_CHASSIS_TYPE },
        { "cvr", DMI_CHASSIS_VERSION },
        { NULL,  DMI_NONE }
    };

    ssize_t l, left;
    char *p;
    const struct mafield *f;

    strcpy(buffer, "dmi");
    p = buffer + 3; left = buffer_size - 4;

    for (f = fields; f->prefix && left > 0; f++) {
        const char *c;
        char *t;

        c = dmi_get_system_info(f->field);
        if (!c)
            continue;

        t = kmalloc(strlen(c) + 1, GFP_KERNEL);
        if (!t)
            break;
        ascii_filter(t, c);
        l = scnprintf(p, left, ":%s%s", f->prefix, t);
        kfree(t);

        p += l;
        left -= l;
    }

    p[0] = ':';
    p[1] = 0;

    return p - buffer + 1;
}

static ssize_t sys_dmi_modalias_show(struct device *dev,
                     struct device_attribute *attr, char *page)
{
    ssize_t r;
    r = get_modalias(page, PAGE_SIZE-1);
    page[r] = '\n';
    page[r+1] = 0;
    return r+1;
}

static struct device_attribute sys_dmi_modalias_attr =
    __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL);

static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2];

static struct attribute_group sys_dmi_attribute_group = {
    .attrs = sys_dmi_attributes,
};

static const struct attribute_group* sys_dmi_attribute_groups[] = {
    &sys_dmi_attribute_group,
    NULL
};

static int dmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
{
    ssize_t len;

    if (add_uevent_var(env, "MODALIAS="))
        return -ENOMEM;
    len = get_modalias(&env->buf[env->buflen - 1],
               sizeof(env->buf) - env->buflen);
    if (len >= (sizeof(env->buf) - env->buflen))
        return -ENOMEM;
    env->buflen += len;
    return 0;
}

static struct class dmi_class = {
    .name = "dmi",
    .dev_release = (void(*)(struct device *)) kfree,
    .dev_uevent = dmi_dev_uevent,
};

static struct device *dmi_dev;

/* Initialization */

#define ADD_DMI_ATTR(_name, _field) \
    if (dmi_get_system_info(_field)) \
        sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr;

/* In a separate function to keep gcc 3.2 happy - do NOT merge this in
   dmi_id_init! */
static void __init dmi_id_init_attr_table(void)
{
    int i;

    /* Not necessarily all DMI fields are available on all
     * systems, hence let's built an attribute table of just
     * what's available */
    i = 0;
    ADD_DMI_ATTR(bios_vendor,       DMI_BIOS_VENDOR);
    ADD_DMI_ATTR(bios_version,      DMI_BIOS_VERSION);
    ADD_DMI_ATTR(bios_date,         DMI_BIOS_DATE);
    ADD_DMI_ATTR(sys_vendor,        DMI_SYS_VENDOR);
    ADD_DMI_ATTR(product_name,      DMI_PRODUCT_NAME);
    ADD_DMI_ATTR(product_version,   DMI_PRODUCT_VERSION);
    ADD_DMI_ATTR(product_serial,    DMI_PRODUCT_SERIAL);
    ADD_DMI_ATTR(product_uuid,      DMI_PRODUCT_UUID);
    ADD_DMI_ATTR(board_vendor,      DMI_BOARD_VENDOR);
    ADD_DMI_ATTR(board_name,        DMI_BOARD_NAME);
    ADD_DMI_ATTR(board_version,     DMI_BOARD_VERSION);
    ADD_DMI_ATTR(board_serial,      DMI_BOARD_SERIAL);
    ADD_DMI_ATTR(board_asset_tag,   DMI_BOARD_ASSET_TAG);
    ADD_DMI_ATTR(chassis_vendor,    DMI_CHASSIS_VENDOR);
    ADD_DMI_ATTR(chassis_type,      DMI_CHASSIS_TYPE);
    ADD_DMI_ATTR(chassis_version,   DMI_CHASSIS_VERSION);
    ADD_DMI_ATTR(chassis_serial,    DMI_CHASSIS_SERIAL);
    ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG);
    sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr;
}

static int __init dmi_id_init(void)
{
    int ret;

    if (!dmi_available)
        return -ENODEV;

    dmi_id_init_attr_table();

    ret = class_register(&dmi_class);
    if (ret)
        return ret;

    dmi_dev = kzalloc(sizeof(*dmi_dev), GFP_KERNEL);
    if (!dmi_dev) {
        ret = -ENOMEM;
        goto fail_class_unregister;
    }

    dmi_dev->class = &dmi_class;
    dev_set_name(dmi_dev, "id");
    dmi_dev->groups = sys_dmi_attribute_groups;

    ret = device_register(dmi_dev);
    if (ret)
        goto fail_free_dmi_dev;

    return 0;

fail_free_dmi_dev:
    kfree(dmi_dev);
fail_class_unregister:

    class_unregister(&dmi_class);

    return ret;
}

arch_initcall(dmi_id_init);