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
|
/*
* Copyright (C) 2021 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.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <string.h>
#include <errno.h>
#include <ipxe/umalloc.h>
#include <ipxe/linux_api.h>
#include <ipxe/linux.h>
#include <ipxe/linux_sysfs.h>
/** @file
*
* Linux sysfs files
*
*/
/**
* Read file from sysfs
*
* @v filename Filename
* @v data Data to fill in
* @ret len Length read, or negative error
*/
int linux_sysfs_read ( const char *filename, userptr_t *data ) {
struct statx statx;
size_t offset;
size_t len;
ssize_t read;
int fd;
int rc;
/* Open file */
fd = linux_open ( filename, O_RDONLY );
if ( fd < 0 ) {
rc = -ELINUX ( linux_errno );
DBGC ( filename, "LINUX could not open %s: %s\n",
filename, linux_strerror ( linux_errno ) );
goto err_open;
}
/* Get file length */
if ( linux_statx ( fd, "", AT_EMPTY_PATH, STATX_SIZE, &statx ) == -1 ) {
rc = -ELINUX ( linux_errno );
DBGC ( filename, "LINUX could not stat %s: %s\n",
filename, linux_strerror ( linux_errno ) );
goto err_stat;
}
len = statx.stx_size;
/* Allocate buffer */
*data = umalloc ( len );
if ( ! *data ) {
rc = -ENOMEM;
DBGC ( filename, "LINUX could not allocate %zd bytes for %s\n",
len, filename );
goto err_alloc;
}
/* Read file */
for ( offset = 0 ; offset < len ; offset += read ) {
read = linux_read ( fd, user_to_virt ( *data, offset ), len );
if ( read < 0 ) {
DBGC ( filename, "LINUX could not read %s: %s\n",
filename, linux_strerror ( linux_errno ) );
goto err_read;
}
if ( read == 0 ) {
rc = -EIO;
DBGC ( filename, "LINUX read underlength %s\n",
filename );
goto err_eof;
}
}
/* Close file */
linux_close ( fd );
DBGC ( filename, "LINUX read %s\n", filename );
return len;
err_eof:
err_read:
ufree ( *data );
err_alloc:
err_stat:
linux_close ( fd );
err_open:
return rc;
}
|
