aboutsummaryrefslogtreecommitdiff
path: root/drivers/platform/x86/dell-wmi-sysman/passobj-attributes.c
blob: 3abcd95477c0789d67aabc1e01b8bc5435e192eb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
// SPDX-License-Identifier: GPL-2.0
/*
 * Functions corresponding to password object type attributes under BIOS Password Object GUID for
 * use with dell-wmi-sysman
 *
 *  Copyright (c) 2020 Dell Inc.
 */

#include "dell-wmi-sysman.h"

enum po_properties {IS_PASS_SET = 1, MIN_PASS_LEN, MAX_PASS_LEN};

get_instance_id(po);

static ssize_t is_enabled_show(struct kobject *kobj, struct kobj_attribute *attr,
					  char *buf)
{
	int instance_id = get_po_instance_id(kobj);
	union acpi_object *obj;
	ssize_t ret;

	if (instance_id < 0)
		return instance_id;

	/* need to use specific instance_id and guid combination to get right data */
	obj = get_wmiobj_pointer(instance_id, DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
	if (!obj)
		return -EIO;
	if (obj->package.elements[IS_PASS_SET].type != ACPI_TYPE_INTEGER) {
		kfree(obj);
		return -EINVAL;
	}
	ret = snprintf(buf, PAGE_SIZE, "%lld\n", obj->package.elements[IS_PASS_SET].integer.value);
	kfree(obj);
	return ret;
}

static struct kobj_attribute po_is_pass_set = __ATTR_RO(is_enabled);

static ssize_t current_password_store(struct kobject *kobj,
				      struct kobj_attribute *attr,
				      const char *buf, size_t count)
{
	char *target = NULL;
	int length;

	length = strlen(buf);
	if (buf[length-1] == '\n')
		length--;

	/* firmware does verifiation of min/max password length,
	 * hence only check for not exceeding MAX_BUFF here.
	 */
	if (length >= MAX_BUFF)
		return -EINVAL;

	if (strcmp(kobj->name, "Admin") == 0)
		target = wmi_priv.current_admin_password;
	else if (strcmp(kobj->name, "System") == 0)
		target = wmi_priv.current_system_password;
	if (!target)
		return -EIO;
	memcpy(target, buf, length);
	target[length] = '\0';

	return count;
}

static struct kobj_attribute po_current_password = __ATTR_WO(current_password);

static ssize_t new_password_store(struct kobject *kobj,
				  struct kobj_attribute *attr,
				  const char *buf, size_t count)
{
	char *p, *buf_cp;
	int ret;

	buf_cp = kstrdup(buf, GFP_KERNEL);
	if (!buf_cp)
		return -ENOMEM;
	p = memchr(buf_cp, '\n', count);

	if (p != NULL)
		*p = '\0';
	if (strlen(buf_cp) > MAX_BUFF) {
		ret = -EINVAL;
		goto out;
	}

	ret = set_new_password(kobj->name, buf_cp);

out:
	kfree(buf_cp);
	return ret ? ret : count;
}

static struct kobj_attribute po_new_password = __ATTR_WO(new_password);

attribute_n_property_show(min_password_length, po);
static struct kobj_attribute po_min_pass_length = __ATTR_RO(min_password_length);

attribute_n_property_show(max_password_length, po);
static struct kobj_attribute po_max_pass_length = __ATTR_RO(max_password_length);

static ssize_t mechanism_show(struct kobject *kobj, struct kobj_attribute *attr,
			 char *buf)
{
	return sprintf(buf, "password\n");
}

static struct kobj_attribute po_mechanism = __ATTR_RO(mechanism);

static ssize_t role_show(struct kobject *kobj, struct kobj_attribute *attr,
			 char *buf)
{
	if (strcmp(kobj->name, "Admin") == 0)
		return sprintf(buf, "bios-admin\n");
	else if (strcmp(kobj->name, "System") == 0)
		return sprintf(buf, "power-on\n");
	return -EIO;
}

static struct kobj_attribute po_role = __ATTR_RO(role);

static struct attribute *po_attrs[] = {
	&po_is_pass_set.attr,
	&po_min_pass_length.attr,
	&po_max_pass_length.attr,
	&po_current_password.attr,
	&po_new_password.attr,
	&po_role.attr,
	&po_mechanism.attr,
	NULL,
};

static const struct attribute_group po_attr_group = {
	.attrs = po_attrs,
};

int alloc_po_data(void)
{
	int ret = 0;

	wmi_priv.po_instances_count = get_instance_count(DELL_WMI_BIOS_PASSOBJ_ATTRIBUTE_GUID);
	wmi_priv.po_data = kcalloc(wmi_priv.po_instances_count, sizeof(struct po_data), GFP_KERNEL);
	if (!wmi_priv.po_data) {
		wmi_priv.po_instances_count = 0;
		ret = -ENOMEM;
	}
	return ret;
}

/**
 * populate_po_data() - Populate all properties of an instance under password object attribute
 * @po_obj: ACPI object with password object data
 * @instance_id: The instance to enumerate
 * @attr_name_kobj: The parent kernel object
 */
int populate_po_data(union acpi_object *po_obj, int instance_id, struct kobject *attr_name_kobj)
{
	wmi_priv.po_data[instance_id].attr_name_kobj = attr_name_kobj;
	strlcpy_attr(wmi_priv.po_data[instance_id].attribute_name,
		     po_obj[ATTR_NAME].string.pointer);
	wmi_priv.po_data[instance_id].min_password_length =
		(uintptr_t)po_obj[MIN_PASS_LEN].string.pointer;
	wmi_priv.po_data[instance_id].max_password_length =
		(uintptr_t) po_obj[MAX_PASS_LEN].string.pointer;

	return sysfs_create_group(attr_name_kobj, &po_attr_group);
}

/**
 * exit_po_attributes() - Clear all attribute data
 *
 * Clears all data allocated for this group of attributes
 */
void exit_po_attributes(void)
{
	int instance_id;

	for (instance_id = 0; instance_id < wmi_priv.po_instances_count; instance_id++) {
		if (wmi_priv.po_data[instance_id].attr_name_kobj)
			sysfs_remove_group(wmi_priv.po_data[instance_id].attr_name_kobj,
								&po_attr_group);
	}
	kfree(wmi_priv.po_data);
}