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
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/*
* Copyright (C) 2023 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/**
* @file
*
* EFI variable settings
*
*/
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ipxe/settings.h>
#include <ipxe/init.h>
#include <ipxe/efi/efi.h>
#include <ipxe/efi/efi_strings.h>
/** EFI variable settings scope */
static const struct settings_scope efivars_scope;
/** EFI variable settings */
static struct settings efivars;
/**
* Check applicability of EFI variable setting
*
* @v settings Settings block
* @v setting Setting
* @ret applies Setting applies within this settings block
*/
static int efivars_applies ( struct settings *settings __unused,
const struct setting *setting ) {
return ( setting->scope == &efivars_scope );
}
/**
* Find first matching EFI variable name
*
* @v wname Name
* @v guid GUID to fill in
* @ret rc Return status code
*/
static int efivars_find ( const CHAR16 *wname, EFI_GUID *guid ) {
EFI_RUNTIME_SERVICES *rs = efi_systab->RuntimeServices;
size_t wname_len = ( ( wcslen ( wname ) + 1 ) * sizeof ( wname[0] ) );
CHAR16 *buf;
CHAR16 *tmp;
UINTN size;
EFI_STATUS efirc;
int rc;
/* Allocate single wNUL for first call to GetNextVariableName() */
size = sizeof ( buf[0] );
buf = zalloc ( size );
if ( ! buf )
return -ENOMEM;
/* Iterate over all veriables */
while ( 1 ) {
/* Get next variable name */
efirc = rs->GetNextVariableName ( &size, buf, guid );
if ( efirc == EFI_BUFFER_TOO_SMALL ) {
tmp = realloc ( buf, size );
if ( ! tmp ) {
rc = -ENOMEM;
break;
}
buf = tmp;
efirc = rs->GetNextVariableName ( &size, buf, guid );
}
if ( efirc == EFI_NOT_FOUND ) {
rc = -ENOENT;
break;
}
if ( efirc != 0 ) {
rc = -EEFI ( efirc );
DBGC ( &efivars, "EFIVARS %s:%ls could not fetch next "
"variable name: %s\n",
efi_guid_ntoa ( guid ), buf, strerror ( rc ) );
break;
}
DBGC2 ( &efivars, "EFIVARS %s:%ls exists\n",
efi_guid_ntoa ( guid ), buf );
/* Check for matching variable name */
if ( memcmp ( wname, buf, wname_len ) == 0 ) {
rc = 0;
break;
}
}
/* Free temporary buffer */
free ( buf );
return rc;
}
/**
* Fetch value of EFI variable setting
*
* @v settings Settings block
* @v setting Setting to fetch
* @v data Buffer to fill with setting data
* @v len Length of buffer
* @ret len Length of setting data, or negative error
*/
static int efivars_fetch ( struct settings *settings __unused,
struct setting *setting, void *data, size_t len ) {
EFI_RUNTIME_SERVICES *rs = efi_systab->RuntimeServices;
size_t name_len = strlen ( setting->name );
CHAR16 wname[ name_len + 1 /* wNUL */ ];
EFI_GUID guid;
UINT32 attrs;
UINTN size;
void *buf;
EFI_STATUS efirc;
int rc;
/* Convert name to UCS-2 */
efi_snprintf ( wname, sizeof ( wname ), "%s", setting->name );
/* Find variable GUID */
if ( ( rc = efivars_find ( wname, &guid ) ) != 0 )
goto err_find;
/* Get variable length */
size = 0;
if ( ( efirc = rs->GetVariable ( wname, &guid, &attrs, &size,
NULL ) != EFI_BUFFER_TOO_SMALL ) ) {
rc = -EEFI ( efirc );
DBGC ( &efivars, "EFIVARS %s:%ls could not get size: %s\n",
efi_guid_ntoa ( &guid ), wname, strerror ( rc ) );
goto err_len;
}
/* Allocate temporary buffer, since GetVariable() is not
* guaranteed to return partial data for an underlength
* buffer.
*/
buf = malloc ( size );
if ( ! buf ) {
rc = -ENOMEM;
goto err_alloc;
}
/* Get variable value */
if ( ( efirc = rs->GetVariable ( wname, &guid, &attrs, &size,
buf ) ) != 0 ) {
rc = -EEFI ( efirc );
DBGC ( &efivars, "EFIVARS %s:%ls could not get %zd bytes: "
"%s\n", efi_guid_ntoa ( &guid ), wname,
( ( size_t ) size ), strerror ( rc ) );
goto err_get;
}
DBGC ( &efivars, "EFIVARS %s:%ls:\n", efi_guid_ntoa ( &guid ), wname );
DBGC_HDA ( &efivars, 0, buf, size );
/* Return setting value */
if ( len > size )
len = size;
memcpy ( data, buf, len );
if ( ! setting->type )
setting->type = &setting_type_hex;
/* Free temporary buffer */
free ( buf );
return size;
err_get:
free ( buf );
err_alloc:
err_len:
err_find:
return rc;
}
/** EFI variable settings operations */
static struct settings_operations efivars_operations = {
.applies = efivars_applies,
.fetch = efivars_fetch,
};
/** EFI variable settings */
static struct settings efivars = {
.refcnt = NULL,
.siblings = LIST_HEAD_INIT ( efivars.siblings ),
.children = LIST_HEAD_INIT ( efivars.children ),
.op = &efivars_operations,
.default_scope = &efivars_scope,
};
/**
* Initialise EFI variable settings
*
*/
static void efivars_init ( void ) {
int rc;
/* Register settings block */
if ( ( rc = register_settings ( &efivars, NULL, "efi" ) ) != 0 ) {
DBGC ( &efivars, "EFIVARS could not register: %s\n",
strerror ( rc ) );
return;
}
}
/** EFI variable settings initialiser */
struct init_fn efivars_init_fn __init_fn ( INIT_NORMAL ) = {
.initialise = efivars_init,
};
|