1 /*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * $FreeBSD$
30 */
31 #ifndef _LINUX_SYSFS_H_
32 #define _LINUX_SYSFS_H_
33
34 #include <sys/types.h>
35 #include <sys/sysctl.h>
36 #include <sys/errno.h>
37
38 #include <linux/kobject.h>
39
40 struct sysfs_ops {
41 ssize_t (*show)(struct kobject *, struct attribute *, char *);
42 ssize_t (*store)(struct kobject *, struct attribute *, const char *,
43 size_t);
44 };
45
46 struct attribute_group {
47 const char *name;
48 mode_t (*is_visible)(struct kobject *,
49 struct attribute *, int);
50 struct attribute **attrs;
51 };
52
53 #define __ATTR(_name, _mode, _show, _store) { \
54 .attr = { .name = __stringify(_name), .mode = _mode }, \
55 .show = _show, .store = _store, \
56 }
57
58 #define __ATTR_RO(_name) { \
59 .attr = { .name = __stringify(_name), .mode = 0444 }, \
60 .show = _name##_show, \
61 }
62
63 #define __ATTR_NULL { .attr = { .name = NULL } }
64
65 /*
66 * Handle our generic '\0' terminated 'C' string.
67 * Two cases:
68 * a variable string: point arg1 at it, arg2 is max length.
69 * a constant string: point arg1 at it, arg2 is zero.
70 */
71
72 static inline int
sysctl_handle_attr(SYSCTL_HANDLER_ARGS)73 sysctl_handle_attr(SYSCTL_HANDLER_ARGS)
74 {
75 struct kobject *kobj;
76 struct attribute *attr;
77 const struct sysfs_ops *ops;
78 char *buf;
79 int error;
80 ssize_t len;
81
82 kobj = arg1;
83 attr = (struct attribute *)(intptr_t)arg2;
84 if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL)
85 return (ENODEV);
86 buf = (char *)get_zeroed_page(GFP_KERNEL);
87 if (buf == NULL)
88 return (ENOMEM);
89 ops = kobj->ktype->sysfs_ops;
90 if (ops->show) {
91 len = ops->show(kobj, attr, buf);
92 /*
93 * It's valid to not have a 'show' so just return an
94 * empty string.
95 */
96 if (len < 0) {
97 error = -len;
98 if (error != EIO)
99 goto out;
100 buf[0] = '\0';
101 } else if (len) {
102 len--;
103 if (len >= PAGE_SIZE)
104 len = PAGE_SIZE - 1;
105 /* Trim trailing newline. */
106 buf[len] = '\0';
107 }
108 }
109
110 /* Leave one trailing byte to append a newline. */
111 error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req);
112 if (error != 0 || req->newptr == NULL || ops->store == NULL)
113 goto out;
114 len = strlcat(buf, "\n", PAGE_SIZE);
115 KASSERT(len < PAGE_SIZE, ("new attribute truncated"));
116 len = ops->store(kobj, attr, buf, len);
117 if (len < 0)
118 error = -len;
119 out:
120 free_page((unsigned long)buf);
121
122 return (error);
123 }
124
125 static inline int
sysfs_create_file(struct kobject * kobj,const struct attribute * attr)126 sysfs_create_file(struct kobject *kobj, const struct attribute *attr)
127 {
128
129 sysctl_add_oid(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO,
130 attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj,
131 (uintptr_t)attr, sysctl_handle_attr, "A", "");
132
133 return (0);
134 }
135
136 static inline void
sysfs_remove_file(struct kobject * kobj,const struct attribute * attr)137 sysfs_remove_file(struct kobject *kobj, const struct attribute *attr)
138 {
139
140 if (kobj->oidp)
141 sysctl_remove_name(kobj->oidp, attr->name, 1, 1);
142 }
143
144 static inline void
sysfs_remove_group(struct kobject * kobj,const struct attribute_group * grp)145 sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp)
146 {
147
148 if (kobj->oidp)
149 sysctl_remove_name(kobj->oidp, grp->name, 1, 1);
150 }
151
152 static inline int
sysfs_create_group(struct kobject * kobj,const struct attribute_group * grp)153 sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp)
154 {
155 struct attribute **attr;
156 struct sysctl_oid *oidp;
157
158 oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp),
159 OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name);
160 for (attr = grp->attrs; *attr != NULL; attr++) {
161 sysctl_add_oid(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO,
162 (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE,
163 kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", "");
164 }
165
166 return (0);
167 }
168
169 static inline int
sysfs_create_dir(struct kobject * kobj)170 sysfs_create_dir(struct kobject *kobj)
171 {
172
173 kobj->oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp),
174 OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name);
175
176 return (0);
177 }
178
179 static inline void
sysfs_remove_dir(struct kobject * kobj)180 sysfs_remove_dir(struct kobject *kobj)
181 {
182
183 if (kobj->oidp == NULL)
184 return;
185 sysctl_remove_oid(kobj->oidp, 1, 1);
186 }
187
188 #define sysfs_attr_init(attr) do {} while(0)
189
190 #endif /* _LINUX_SYSFS_H_ */
191