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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * xt_LED.c - netfilter target to make LEDs blink upon packet matches
4 *
5 * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net>
6 */
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8#include <linux/module.h>
9#include <linux/skbuff.h>
10#include <linux/netfilter/x_tables.h>
11#include <linux/slab.h>
12#include <linux/leds.h>
13#include <linux/mutex.h>
14
15#include <linux/netfilter/xt_LED.h>
16
17MODULE_LICENSE("GPL");
18MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");
19MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");
20MODULE_ALIAS("ipt_LED");
21MODULE_ALIAS("ip6t_LED");
22
23static LIST_HEAD(xt_led_triggers);
24static DEFINE_MUTEX(xt_led_mutex);
25
26/*
27 * This is declared in here (the kernel module) only, to avoid having these
28 * dependencies in userspace code. This is what xt_led_info.internal_data
29 * points to.
30 */
31struct xt_led_info_internal {
32 struct list_head list;
33 int refcnt;
34 char *trigger_id;
35 struct led_trigger netfilter_led_trigger;
36 struct timer_list timer;
37};
38
39#define XT_LED_BLINK_DELAY 50 /* ms */
40
41static unsigned int
42led_tg(struct sk_buff *skb, const struct xt_action_param *par)
43{
44 const struct xt_led_info *ledinfo = par->targinfo;
45 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
46 unsigned long led_delay = XT_LED_BLINK_DELAY;
47
48 /*
49 * If "always blink" is enabled, and there's still some time until the
50 * LED will switch off, briefly switch it off now.
51 */
52 if ((ledinfo->delay > 0) && ledinfo->always_blink &&
53 timer_pending(&ledinternal->timer))
54 led_trigger_blink_oneshot(&ledinternal->netfilter_led_trigger,
55 &led_delay, &led_delay, 1);
56 else
57 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);
58
59 /* If there's a positive delay, start/update the timer */
60 if (ledinfo->delay > 0) {
61 mod_timer(&ledinternal->timer,
62 jiffies + msecs_to_jiffies(ledinfo->delay));
63
64 /* Otherwise if there was no delay given, blink as fast as possible */
65 } else if (ledinfo->delay == 0) {
66 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
67 }
68
69 /* else the delay is negative, which means switch on and stay on */
70
71 return XT_CONTINUE;
72}
73
74static void led_timeout_callback(struct timer_list *t)
75{
76 struct xt_led_info_internal *ledinternal = from_timer(ledinternal, t,
77 timer);
78
79 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
80}
81
82static struct xt_led_info_internal *led_trigger_lookup(const char *name)
83{
84 struct xt_led_info_internal *ledinternal;
85
86 list_for_each_entry(ledinternal, &xt_led_triggers, list) {
87 if (!strcmp(name, ledinternal->netfilter_led_trigger.name)) {
88 return ledinternal;
89 }
90 }
91 return NULL;
92}
93
94static int led_tg_check(const struct xt_tgchk_param *par)
95{
96 struct xt_led_info *ledinfo = par->targinfo;
97 struct xt_led_info_internal *ledinternal;
98 int err;
99
100 if (ledinfo->id[0] == '\0')
101 return -EINVAL;
102
103 mutex_lock(&xt_led_mutex);
104
105 ledinternal = led_trigger_lookup(ledinfo->id);
106 if (ledinternal) {
107 ledinternal->refcnt++;
108 goto out;
109 }
110
111 err = -ENOMEM;
112 ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
113 if (!ledinternal)
114 goto exit_mutex_only;
115
116 ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL);
117 if (!ledinternal->trigger_id)
118 goto exit_internal_alloc;
119
120 ledinternal->refcnt = 1;
121 ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id;
122
123 err = led_trigger_register(&ledinternal->netfilter_led_trigger);
124 if (err) {
125 pr_info_ratelimited("Trigger name is already in use.\n");
126 goto exit_alloc;
127 }
128
129 /* Since the letinternal timer can be shared between multiple targets,
130 * always set it up, even if the current target does not need it
131 */
132 timer_setup(&ledinternal->timer, led_timeout_callback, 0);
133
134 list_add_tail(&ledinternal->list, &xt_led_triggers);
135
136out:
137 mutex_unlock(&xt_led_mutex);
138
139 ledinfo->internal_data = ledinternal;
140
141 return 0;
142
143exit_alloc:
144 kfree(ledinternal->trigger_id);
145
146exit_internal_alloc:
147 kfree(ledinternal);
148
149exit_mutex_only:
150 mutex_unlock(&xt_led_mutex);
151
152 return err;
153}
154
155static void led_tg_destroy(const struct xt_tgdtor_param *par)
156{
157 const struct xt_led_info *ledinfo = par->targinfo;
158 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
159
160 mutex_lock(&xt_led_mutex);
161
162 if (--ledinternal->refcnt) {
163 mutex_unlock(&xt_led_mutex);
164 return;
165 }
166
167 list_del(&ledinternal->list);
168
169 del_timer_sync(&ledinternal->timer);
170
171 led_trigger_unregister(&ledinternal->netfilter_led_trigger);
172
173 mutex_unlock(&xt_led_mutex);
174
175 kfree(ledinternal->trigger_id);
176 kfree(ledinternal);
177}
178
179static struct xt_target led_tg_reg __read_mostly = {
180 .name = "LED",
181 .revision = 0,
182 .family = NFPROTO_UNSPEC,
183 .target = led_tg,
184 .targetsize = sizeof(struct xt_led_info),
185 .usersize = offsetof(struct xt_led_info, internal_data),
186 .checkentry = led_tg_check,
187 .destroy = led_tg_destroy,
188 .me = THIS_MODULE,
189};
190
191static int __init led_tg_init(void)
192{
193 return xt_register_target(&led_tg_reg);
194}
195
196static void __exit led_tg_exit(void)
197{
198 xt_unregister_target(&led_tg_reg);
199}
200
201module_init(led_tg_init);
202module_exit(led_tg_exit);
1/*
2 * xt_LED.c - netfilter target to make LEDs blink upon packet matches
3 *
4 * Copyright (C) 2008 Adam Nielsen <a.nielsen@shikadi.net>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18 * 02110-1301 USA.
19 *
20 */
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22#include <linux/module.h>
23#include <linux/skbuff.h>
24#include <linux/netfilter/x_tables.h>
25#include <linux/slab.h>
26#include <linux/leds.h>
27#include <linux/mutex.h>
28
29#include <linux/netfilter/xt_LED.h>
30
31MODULE_LICENSE("GPL");
32MODULE_AUTHOR("Adam Nielsen <a.nielsen@shikadi.net>");
33MODULE_DESCRIPTION("Xtables: trigger LED devices on packet match");
34MODULE_ALIAS("ipt_LED");
35MODULE_ALIAS("ip6t_LED");
36
37static LIST_HEAD(xt_led_triggers);
38static DEFINE_MUTEX(xt_led_mutex);
39
40/*
41 * This is declared in here (the kernel module) only, to avoid having these
42 * dependencies in userspace code. This is what xt_led_info.internal_data
43 * points to.
44 */
45struct xt_led_info_internal {
46 struct list_head list;
47 int refcnt;
48 char *trigger_id;
49 struct led_trigger netfilter_led_trigger;
50 struct timer_list timer;
51};
52
53#define XT_LED_BLINK_DELAY 50 /* ms */
54
55static unsigned int
56led_tg(struct sk_buff *skb, const struct xt_action_param *par)
57{
58 const struct xt_led_info *ledinfo = par->targinfo;
59 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
60 unsigned long led_delay = XT_LED_BLINK_DELAY;
61
62 /*
63 * If "always blink" is enabled, and there's still some time until the
64 * LED will switch off, briefly switch it off now.
65 */
66 if ((ledinfo->delay > 0) && ledinfo->always_blink &&
67 timer_pending(&ledinternal->timer))
68 led_trigger_blink_oneshot(&ledinternal->netfilter_led_trigger,
69 &led_delay, &led_delay, 1);
70 else
71 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_FULL);
72
73 /* If there's a positive delay, start/update the timer */
74 if (ledinfo->delay > 0) {
75 mod_timer(&ledinternal->timer,
76 jiffies + msecs_to_jiffies(ledinfo->delay));
77
78 /* Otherwise if there was no delay given, blink as fast as possible */
79 } else if (ledinfo->delay == 0) {
80 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
81 }
82
83 /* else the delay is negative, which means switch on and stay on */
84
85 return XT_CONTINUE;
86}
87
88static void led_timeout_callback(struct timer_list *t)
89{
90 struct xt_led_info_internal *ledinternal = from_timer(ledinternal, t,
91 timer);
92
93 led_trigger_event(&ledinternal->netfilter_led_trigger, LED_OFF);
94}
95
96static struct xt_led_info_internal *led_trigger_lookup(const char *name)
97{
98 struct xt_led_info_internal *ledinternal;
99
100 list_for_each_entry(ledinternal, &xt_led_triggers, list) {
101 if (!strcmp(name, ledinternal->netfilter_led_trigger.name)) {
102 return ledinternal;
103 }
104 }
105 return NULL;
106}
107
108static int led_tg_check(const struct xt_tgchk_param *par)
109{
110 struct xt_led_info *ledinfo = par->targinfo;
111 struct xt_led_info_internal *ledinternal;
112 int err;
113
114 if (ledinfo->id[0] == '\0')
115 return -EINVAL;
116
117 mutex_lock(&xt_led_mutex);
118
119 ledinternal = led_trigger_lookup(ledinfo->id);
120 if (ledinternal) {
121 ledinternal->refcnt++;
122 goto out;
123 }
124
125 err = -ENOMEM;
126 ledinternal = kzalloc(sizeof(struct xt_led_info_internal), GFP_KERNEL);
127 if (!ledinternal)
128 goto exit_mutex_only;
129
130 ledinternal->trigger_id = kstrdup(ledinfo->id, GFP_KERNEL);
131 if (!ledinternal->trigger_id)
132 goto exit_internal_alloc;
133
134 ledinternal->refcnt = 1;
135 ledinternal->netfilter_led_trigger.name = ledinternal->trigger_id;
136
137 err = led_trigger_register(&ledinternal->netfilter_led_trigger);
138 if (err) {
139 pr_info_ratelimited("Trigger name is already in use.\n");
140 goto exit_alloc;
141 }
142
143 /* Since the letinternal timer can be shared between multiple targets,
144 * always set it up, even if the current target does not need it
145 */
146 timer_setup(&ledinternal->timer, led_timeout_callback, 0);
147
148 list_add_tail(&ledinternal->list, &xt_led_triggers);
149
150out:
151 mutex_unlock(&xt_led_mutex);
152
153 ledinfo->internal_data = ledinternal;
154
155 return 0;
156
157exit_alloc:
158 kfree(ledinternal->trigger_id);
159
160exit_internal_alloc:
161 kfree(ledinternal);
162
163exit_mutex_only:
164 mutex_unlock(&xt_led_mutex);
165
166 return err;
167}
168
169static void led_tg_destroy(const struct xt_tgdtor_param *par)
170{
171 const struct xt_led_info *ledinfo = par->targinfo;
172 struct xt_led_info_internal *ledinternal = ledinfo->internal_data;
173
174 mutex_lock(&xt_led_mutex);
175
176 if (--ledinternal->refcnt) {
177 mutex_unlock(&xt_led_mutex);
178 return;
179 }
180
181 list_del(&ledinternal->list);
182
183 del_timer_sync(&ledinternal->timer);
184
185 led_trigger_unregister(&ledinternal->netfilter_led_trigger);
186
187 mutex_unlock(&xt_led_mutex);
188
189 kfree(ledinternal->trigger_id);
190 kfree(ledinternal);
191}
192
193static struct xt_target led_tg_reg __read_mostly = {
194 .name = "LED",
195 .revision = 0,
196 .family = NFPROTO_UNSPEC,
197 .target = led_tg,
198 .targetsize = sizeof(struct xt_led_info),
199 .usersize = offsetof(struct xt_led_info, internal_data),
200 .checkentry = led_tg_check,
201 .destroy = led_tg_destroy,
202 .me = THIS_MODULE,
203};
204
205static int __init led_tg_init(void)
206{
207 return xt_register_target(&led_tg_reg);
208}
209
210static void __exit led_tg_exit(void)
211{
212 xt_unregister_target(&led_tg_reg);
213}
214
215module_init(led_tg_init);
216module_exit(led_tg_exit);